Господин Экзамен

Другие калькуляторы

sin(7*a)+sin(a) если a=3

Выражение, которое надо упростить:

Решение

Вы ввели [src]
sin(7*a) + sin(a)
$$\sin{\left(a \right)} + \sin{\left(7 a \right)}$$
sin(7*a) + sin(a)
Подстановка условия [src]
sin(7*a) + sin(a) при a = 3
подставляем
sin(7*a) + sin(a)
$$\sin{\left(a \right)} + \sin{\left(7 a \right)}$$
sin(a) + sin(7*a)
$$\sin{\left(a \right)} + \sin{\left(7 a \right)}$$
переменные
a = 3
$$a = 3$$
sin((3)) + sin(7*(3))
$$\sin{\left((3) \right)} + \sin{\left(7 (3) \right)}$$
sin(3) + sin(7*3)
$$\sin{\left(3 \right)} + \sin{\left(7 \cdot 3 \right)}$$
sin(3) + sin(21)
$$\sin{\left(3 \right)} + \sin{\left(21 \right)}$$
sin(3) + sin(21)
Степени [src]
    /   -I*a    I*a\     /   -7*I*a    7*I*a\
  I*\- e     + e   /   I*\- e       + e     /
- ------------------ - ----------------------
          2                      2           
$$- \frac{i \left(e^{i a} - e^{- i a}\right)}{2} - \frac{i \left(e^{7 i a} - e^{- 7 i a}\right)}{2}$$
-i*(-exp(-i*a) + exp(i*a))/2 - i*(-exp(-7*i*a) + exp(7*i*a))/2
Раскрыть выражение [src]
        7            3                        5   
- 64*sin (a) - 56*sin (a) + 8*sin(a) + 112*sin (a)
$$- 64 \sin^{7}{\left(a \right)} + 112 \sin^{5}{\left(a \right)} - 56 \sin^{3}{\left(a \right)} + 8 \sin{\left(a \right)}$$
     7            4       3           6                   2       5            
- sin (a) - 35*cos (a)*sin (a) + 7*cos (a)*sin(a) + 21*cos (a)*sin (a) + sin(a)
$$- \sin^{7}{\left(a \right)} + 21 \sin^{5}{\left(a \right)} \cos^{2}{\left(a \right)} - 35 \sin^{3}{\left(a \right)} \cos^{4}{\left(a \right)} + 7 \sin{\left(a \right)} \cos^{6}{\left(a \right)} + \sin{\left(a \right)}$$
-sin(a)^7 - 35*cos(a)^4*sin(a)^3 + 7*cos(a)^6*sin(a) + 21*cos(a)^2*sin(a)^5 + sin(a)
Тригонометрическая часть [src]
2*cos(3*a)*sin(4*a)
$$2 \sin{\left(4 a \right)} \cos{\left(3 a \right)}$$
  1         1    
------ + --------
csc(a)   csc(7*a)
$$\frac{1}{\csc{\left(7 a \right)}} + \frac{1}{\csc{\left(a \right)}}$$
   /    pi\      /      pi\
cos|a - --| + cos|7*a - --|
   \    2 /      \      2 /
$$\cos{\left(a - \frac{\pi}{2} \right)} + \cos{\left(7 a - \frac{\pi}{2} \right)}$$
     1              1      
----------- + -------------
csc(pi - a)   csc(pi - 7*a)
$$\frac{1}{\csc{\left(- a + \pi \right)}} + \frac{1}{\csc{\left(- 7 a + \pi \right)}}$$
     1              1      
----------- + -------------
   /    pi\      /      pi\
sec|a - --|   sec|7*a - --|
   \    2 /      \      2 /
$$\frac{1}{\sec{\left(7 a - \frac{\pi}{2} \right)}} + \frac{1}{\sec{\left(a - \frac{\pi}{2} \right)}}$$
     1              1      
----------- + -------------
   /pi    \      /pi      \
sec|-- - a|   sec|-- - 7*a|
   \2     /      \2       /
$$\frac{1}{\sec{\left(- a + \frac{\pi}{2} \right)}} + \frac{1}{\sec{\left(- 7 a + \frac{\pi}{2} \right)}}$$
                /a\                     /7*a\
(1 + cos(a))*tan|-| + (1 + cos(7*a))*tan|---|
                \2/                     \ 2 /
$$\left(\cos{\left(a \right)} + 1\right) \tan{\left(\frac{a}{2} \right)} + \left(\cos{\left(7 a \right)} + 1\right) \tan{\left(\frac{7 a}{2} \right)}$$
       /a\           /7*a\ 
  2*cot|-|      2*cot|---| 
       \2/           \ 2 / 
----------- + -------------
       2/a\          2/7*a\
1 + cot |-|   1 + cot |---|
        \2/           \ 2 /
$$\frac{2 \cot{\left(\frac{7 a}{2} \right)}}{\cot^{2}{\left(\frac{7 a}{2} \right)} + 1} + \frac{2 \cot{\left(\frac{a}{2} \right)}}{\cot^{2}{\left(\frac{a}{2} \right)} + 1}$$
       /a\           /7*a\ 
  2*tan|-|      2*tan|---| 
       \2/           \ 2 / 
----------- + -------------
       2/a\          2/7*a\
1 + tan |-|   1 + tan |---|
        \2/           \ 2 /
$$\frac{2 \tan{\left(\frac{7 a}{2} \right)}}{\tan^{2}{\left(\frac{7 a}{2} \right)} + 1} + \frac{2 \tan{\left(\frac{a}{2} \right)}}{\tan^{2}{\left(\frac{a}{2} \right)} + 1}$$
         2                        2            
-------------------- + ------------------------
/       1   \    /a\   /        1    \    /7*a\
|1 + -------|*cot|-|   |1 + ---------|*cot|---|
|       2/a\|    \2/   |       2/7*a\|    \ 2 /
|    cot |-||          |    cot |---||         
\        \2//          \        \ 2 //         
$$\frac{2}{\left(1 + \frac{1}{\cot^{2}{\left(\frac{7 a}{2} \right)}}\right) \cot{\left(\frac{7 a}{2} \right)}} + \frac{2}{\left(1 + \frac{1}{\cot^{2}{\left(\frac{a}{2} \right)}}\right) \cot{\left(\frac{a}{2} \right)}}$$
//  0     for a mod pi = 0\   //   0      for 7*a mod pi = 0\
|<                        | + |<                            |
\\sin(a)     otherwise    /   \\sin(7*a)      otherwise     /
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\sin{\left(a \right)} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\sin{\left(7 a \right)} & \text{otherwise} \end{cases}\right)$$
        2/a   pi\           2/pi   7*a\
-1 + tan |- + --|   -1 + tan |-- + ---|
         \2   4 /            \4     2 /
----------------- + -------------------
        2/a   pi\           2/pi   7*a\
 1 + tan |- + --|    1 + tan |-- + ---|
         \2   4 /            \4     2 /
$$\frac{\tan^{2}{\left(\frac{a}{2} + \frac{\pi}{4} \right)} - 1}{\tan^{2}{\left(\frac{a}{2} + \frac{\pi}{4} \right)} + 1} + \frac{\tan^{2}{\left(\frac{7 a}{2} + \frac{\pi}{4} \right)} - 1}{\tan^{2}{\left(\frac{7 a}{2} + \frac{\pi}{4} \right)} + 1}$$
/       2/a   pi\\                /       2/pi   7*a\\               
|1 - cot |- + --||*(1 + sin(a))   |1 - cot |-- + ---||*(1 + sin(7*a))
\        \2   4 //                \        \4     2 //               
------------------------------- + -----------------------------------
               2                                   2                 
$$\frac{\left(- \cot^{2}{\left(\frac{a}{2} + \frac{\pi}{4} \right)} + 1\right) \left(\sin{\left(a \right)} + 1\right)}{2} + \frac{\left(- \cot^{2}{\left(\frac{7 a}{2} + \frac{\pi}{4} \right)} + 1\right) \left(\sin{\left(7 a \right)} + 1\right)}{2}$$
       2/a   pi\          2/pi   7*a\
1 - cot |- + --|   1 - cot |-- + ---|
        \2   4 /           \4     2 /
---------------- + ------------------
       2/a   pi\          2/pi   7*a\
1 + cot |- + --|   1 + cot |-- + ---|
        \2   4 /           \4     2 /
$$\frac{- \cot^{2}{\left(\frac{a}{2} + \frac{\pi}{4} \right)} + 1}{\cot^{2}{\left(\frac{a}{2} + \frac{\pi}{4} \right)} + 1} + \frac{- \cot^{2}{\left(\frac{7 a}{2} + \frac{\pi}{4} \right)} + 1}{\cot^{2}{\left(\frac{7 a}{2} + \frac{\pi}{4} \right)} + 1}$$
//  0     for a mod pi = 0\   //   0      for 7*a mod pi = 0\
||                        |   ||                            |
|<  1                     | + |<   1                        |
||------     otherwise    |   ||--------      otherwise     |
\\csc(a)                  /   \\csc(7*a)                    /
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{1}{\csc{\left(a \right)}} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{1}{\csc{\left(7 a \right)}} & \text{otherwise} \end{cases}\right)$$
//     0       for a mod pi = 0\   //      0        for 7*a mod pi = 0\
||                             |   ||                                 |
|<   /    pi\                  | + |<   /      pi\                    |
||cos|a - --|     otherwise    |   ||cos|7*a - --|      otherwise     |
\\   \    2 /                  /   \\   \      2 /                    /
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\cos{\left(a - \frac{\pi}{2} \right)} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\cos{\left(7 a - \frac{\pi}{2} \right)} & \text{otherwise} \end{cases}\right)$$
       2/a\                  2/7*a\          
  4*sin |-|*sin(a)      4*sin |---|*sin(7*a) 
        \2/                   \ 2 /          
------------------- + -----------------------
   2           4/a\      2             4/7*a\
sin (a) + 4*sin |-|   sin (7*a) + 4*sin |---|
                \2/                     \ 2 /
$$\frac{4 \sin^{2}{\left(\frac{7 a}{2} \right)} \sin{\left(7 a \right)}}{4 \sin^{4}{\left(\frac{7 a}{2} \right)} + \sin^{2}{\left(7 a \right)}} + \frac{4 \sin^{2}{\left(\frac{a}{2} \right)} \sin{\left(a \right)}}{4 \sin^{4}{\left(\frac{a}{2} \right)} + \sin^{2}{\left(a \right)}}$$
//     0       for a mod pi = 0\   //      0        for 7*a mod pi = 0\
||                             |   ||                                 |
||     1                       |   ||      1                          |
|<-----------     otherwise    | + |<-------------      otherwise     |
||   /    pi\                  |   ||   /      pi\                    |
||sec|a - --|                  |   ||sec|7*a - --|                    |
\\   \    2 /                  /   \\   \      2 /                    /
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{1}{\sec{\left(a - \frac{\pi}{2} \right)}} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{1}{\sec{\left(7 a - \frac{\pi}{2} \right)}} & \text{otherwise} \end{cases}\right)$$
//            /    3*pi\             \   //              /      3*pi\             \
||  1     for |a + ----| mod 2*pi = 0|   ||   1      for |7*a + ----| mod 2*pi = 0|
|<            \     2  /             | + |<              \       2  /             |
||                                   |   ||                                       |
\\sin(a)           otherwise         /   \\sin(7*a)            otherwise          /
$$\left(\begin{cases} 1 & \text{for}\: \left(a + \frac{3 \pi}{2}\right) \bmod 2 \pi = 0 \\\sin{\left(a \right)} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 1 & \text{for}\: \left(7 a + \frac{3 \pi}{2}\right) \bmod 2 \pi = 0 \\\sin{\left(7 a \right)} & \text{otherwise} \end{cases}\right)$$
           2/a\                      2/7*a\        
      4*sin |-|                 4*sin |---|        
            \2/                       \ 2 /        
---------------------- + --------------------------
/         4/a\\          /         4/7*a\\         
|    4*sin |-||          |    4*sin |---||         
|          \2/|          |          \ 2 /|         
|1 + ---------|*sin(a)   |1 + -----------|*sin(7*a)
|        2    |          |        2      |         
\     sin (a) /          \     sin (7*a) /         
$$\frac{4 \sin^{2}{\left(\frac{7 a}{2} \right)}}{\left(\frac{4 \sin^{4}{\left(\frac{7 a}{2} \right)}}{\sin^{2}{\left(7 a \right)}} + 1\right) \sin{\left(7 a \right)}} + \frac{4 \sin^{2}{\left(\frac{a}{2} \right)}}{\left(\frac{4 \sin^{4}{\left(\frac{a}{2} \right)}}{\sin^{2}{\left(a \right)}} + 1\right) \sin{\left(a \right)}}$$
//    0       for a mod pi = 0\   //     0        for 7*a mod pi = 0\
||                            |   ||                                |
||1 - cos(a)                  |   ||1 - cos(7*a)                    |
|<----------     otherwise    | + |<------------      otherwise     |
||     /a\                    |   ||     /7*a\                      |
||  tan|-|                    |   ||  tan|---|                      |
\\     \2/                    /   \\     \ 2 /                      /
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{- \cos{\left(a \right)} + 1}{\tan{\left(\frac{a}{2} \right)}} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{- \cos{\left(7 a \right)} + 1}{\tan{\left(\frac{7 a}{2} \right)}} & \text{otherwise} \end{cases}\right)$$
//     0       for a mod pi = 0\   //      0        for 7*a mod pi = 0\
||                             |   ||                                 |
||       /a\                   |   ||       /7*a\                     |
||  2*tan|-|                   |   ||  2*tan|---|                     |
|<       \2/                   | + |<       \ 2 /                     |
||-----------     otherwise    |   ||-------------      otherwise     |
||       2/a\                  |   ||       2/7*a\                    |
||1 + tan |-|                  |   ||1 + tan |---|                    |
\\        \2/                  /   \\        \ 2 /                    /
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{2 \tan{\left(\frac{a}{2} \right)}}{\tan^{2}{\left(\frac{a}{2} \right)} + 1} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{2 \tan{\left(\frac{7 a}{2} \right)}}{\tan^{2}{\left(\frac{7 a}{2} \right)} + 1} & \text{otherwise} \end{cases}\right)$$
//     0       for a mod pi = 0\   //      0        for 7*a mod pi = 0\
||                             |   ||                                 |
||       /a\                   |   ||       /7*a\                     |
||  2*cot|-|                   |   ||  2*cot|---|                     |
|<       \2/                   | + |<       \ 2 /                     |
||-----------     otherwise    |   ||-------------      otherwise     |
||       2/a\                  |   ||       2/7*a\                    |
||1 + cot |-|                  |   ||1 + cot |---|                    |
\\        \2/                  /   \\        \ 2 /                    /
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{2 \cot{\left(\frac{a}{2} \right)}}{\cot^{2}{\left(\frac{a}{2} \right)} + 1} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{2 \cot{\left(\frac{7 a}{2} \right)}}{\cot^{2}{\left(\frac{7 a}{2} \right)} + 1} & \text{otherwise} \end{cases}\right)$$
//            0              for a mod pi = 0\   //              0                for 7*a mod pi = 0\
||                                           |   ||                                                 |
|
            
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\sin{\left(a \right)} & \text{otherwise} \end{cases} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\sin{\left(7 a \right)} & \text{otherwise} \end{cases} & \text{otherwise} \end{cases}\right)$$
//         0            for a mod pi = 0\   //           0              for 7*a mod pi = 0\
||                                      |   ||                                            |
||         2                            |   ||           2                                |
||--------------------     otherwise    |   ||------------------------      otherwise     |
|
            
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{2}{\left(1 + \frac{1}{\tan^{2}{\left(\frac{a}{2} \right)}}\right) \tan{\left(\frac{a}{2} \right)}} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{2}{\left(1 + \frac{1}{\tan^{2}{\left(\frac{7 a}{2} \right)}}\right) \tan{\left(\frac{7 a}{2} \right)}} & \text{otherwise} \end{cases}\right)$$
                /a\                                 /7*a\              
           2*sec|-|                            2*sec|---|              
                \2/                                 \ 2 /              
------------------------------ + --------------------------------------
/         2/a\   \               /          2/7*a\    \                
|      sec |-|   |               |       sec |---|    |                
|          \2/   |    /a   pi\   |           \ 2 /    |    /  pi   7*a\
|1 + ------------|*sec|- - --|   |1 + ----------------|*sec|- -- + ---|
|       2/a   pi\|    \2   2 /   |       2/  pi   7*a\|    \  2     2 /
|    sec |- - --||               |    sec |- -- + ---||                
\        \2   2 //               \        \  2     2 //                
$$\frac{2 \sec{\left(\frac{7 a}{2} \right)}}{\left(\frac{\sec^{2}{\left(\frac{7 a}{2} \right)}}{\sec^{2}{\left(\frac{7 a}{2} - \frac{\pi}{2} \right)}} + 1\right) \sec{\left(\frac{7 a}{2} - \frac{\pi}{2} \right)}} + \frac{2 \sec{\left(\frac{a}{2} \right)}}{\left(\frac{\sec^{2}{\left(\frac{a}{2} \right)}}{\sec^{2}{\left(\frac{a}{2} - \frac{\pi}{2} \right)}} + 1\right) \sec{\left(\frac{a}{2} - \frac{\pi}{2} \right)}}$$
           /a   pi\                     /  pi   7*a\       
      2*cos|- - --|                2*cos|- -- + ---|       
           \2   2 /                     \  2     2 /       
------------------------- + -------------------------------
/       2/a   pi\\          /       2/  pi   7*a\\         
|    cos |- - --||          |    cos |- -- + ---||         
|        \2   2 /|    /a\   |        \  2     2 /|    /7*a\
|1 + ------------|*cos|-|   |1 + ----------------|*cos|---|
|         2/a\   |    \2/   |          2/7*a\    |    \ 2 /
|      cos |-|   |          |       cos |---|    |         
\          \2/   /          \           \ 2 /    /         
$$\frac{2 \cos{\left(\frac{7 a}{2} - \frac{\pi}{2} \right)}}{\left(1 + \frac{\cos^{2}{\left(\frac{7 a}{2} - \frac{\pi}{2} \right)}}{\cos^{2}{\left(\frac{7 a}{2} \right)}}\right) \cos{\left(\frac{7 a}{2} \right)}} + \frac{2 \cos{\left(\frac{a}{2} - \frac{\pi}{2} \right)}}{\left(1 + \frac{\cos^{2}{\left(\frac{a}{2} - \frac{\pi}{2} \right)}}{\cos^{2}{\left(\frac{a}{2} \right)}}\right) \cos{\left(\frac{a}{2} \right)}}$$
           /pi   a\                     /pi   7*a\       
      2*csc|-- - -|                2*csc|-- - ---|       
           \2    2/                     \2     2 /       
------------------------- + -----------------------------
/       2/pi   a\\          /       2/pi   7*a\\         
|    csc |-- - -||          |    csc |-- - ---||         
|        \2    2/|    /a\   |        \2     2 /|    /7*a\
|1 + ------------|*csc|-|   |1 + --------------|*csc|---|
|         2/a\   |    \2/   |         2/7*a\   |    \ 2 /
|      csc |-|   |          |      csc |---|   |         
\          \2/   /          \          \ 2 /   /         
$$\frac{2 \csc{\left(- \frac{7 a}{2} + \frac{\pi}{2} \right)}}{\left(1 + \frac{\csc^{2}{\left(- \frac{7 a}{2} + \frac{\pi}{2} \right)}}{\csc^{2}{\left(\frac{7 a}{2} \right)}}\right) \csc{\left(\frac{7 a}{2} \right)}} + \frac{2 \csc{\left(- \frac{a}{2} + \frac{\pi}{2} \right)}}{\left(1 + \frac{\csc^{2}{\left(- \frac{a}{2} + \frac{\pi}{2} \right)}}{\csc^{2}{\left(\frac{a}{2} \right)}}\right) \csc{\left(\frac{a}{2} \right)}}$$
//             0                for a mod pi = 0\                                                           
||                                              |                                                           
||          2*sin(a)                            |   //                0                  for 7*a mod pi = 0\
||----------------------------     otherwise    |   ||                                                     |
||             /        2    \                  |   ||    -2*sin(14*a) + 4*sin(7*a)                        |
|<             |     sin (a) |                  | + |<---------------------------------      otherwise     |
||(1 - cos(a))*|1 + ---------|                  |   ||                                2                    |
||             |         4/a\|                  |   ||1 - cos(14*a) + 2*(1 - cos(7*a))                     |
||             |    4*sin |-||                  |   \\                                                     /
||             \          \2//                  |                                                           
\\                                              /                                                           
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{2 \sin{\left(a \right)}}{\left(1 + \frac{\sin^{2}{\left(a \right)}}{4 \sin^{4}{\left(\frac{a}{2} \right)}}\right) \left(- \cos{\left(a \right)} + 1\right)} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{4 \sin{\left(7 a \right)} - 2 \sin{\left(14 a \right)}}{2 \left(- \cos{\left(7 a \right)} + 1\right)^{2} - \cos{\left(14 a \right)} + 1} & \text{otherwise} \end{cases}\right)$$
//                       /    3*pi\             \   //                         /      3*pi\             \
||        1          for |a + ----| mod 2*pi = 0|   ||         1           for |7*a + ----| mod 2*pi = 0|
||                       \     2  /             |   ||                         \       2  /             |
||                                              |   ||                                                  |
||        2/a   pi\                             |   ||        2/pi   7*a\                               |
|<-1 + tan |- + --|                             | + |<-1 + tan |-- + ---|                               |
||         \2   4 /                             |   ||         \4     2 /                               |
||-----------------           otherwise         |   ||-------------------            otherwise          |
||        2/a   pi\                             |   ||        2/pi   7*a\                               |
|| 1 + tan |- + --|                             |   || 1 + tan |-- + ---|                               |
\\         \2   4 /                             /   \\         \4     2 /                               /
$$\left(\begin{cases} 1 & \text{for}\: \left(a + \frac{3 \pi}{2}\right) \bmod 2 \pi = 0 \\\frac{\tan^{2}{\left(\frac{a}{2} + \frac{\pi}{4} \right)} - 1}{\tan^{2}{\left(\frac{a}{2} + \frac{\pi}{4} \right)} + 1} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 1 & \text{for}\: \left(7 a + \frac{3 \pi}{2}\right) \bmod 2 \pi = 0 \\\frac{\tan^{2}{\left(\frac{7 a}{2} + \frac{\pi}{4} \right)} - 1}{\tan^{2}{\left(\frac{7 a}{2} + \frac{\pi}{4} \right)} + 1} & \text{otherwise} \end{cases}\right)$$
//           0             for a mod pi = 0\   //             0               for 7*a mod pi = 0\
||                                         |   ||                                               |
||         sin(a)                          |   ||          sin(7*a)                             |
||-----------------------     otherwise    |   ||---------------------------      otherwise     |
||/        2    \                          |   ||/        2      \                              |
|<|     sin (a) |    2/a\                  | + |<|     sin (7*a) |    2/7*a\                    |
|||1 + ---------|*sin |-|                  |   |||1 + -----------|*sin |---|                    |
|||         4/a\|     \2/                  |   |||         4/7*a\|     \ 2 /                    |
|||    4*sin |-||                          |   |||    4*sin |---||                              |
||\          \2//                          |   ||\          \ 2 //                              |
\\                                         /   \\                                               /
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{\sin{\left(a \right)}}{\left(1 + \frac{\sin^{2}{\left(a \right)}}{4 \sin^{4}{\left(\frac{a}{2} \right)}}\right) \sin^{2}{\left(\frac{a}{2} \right)}} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{\sin{\left(7 a \right)}}{\left(1 + \frac{\sin^{2}{\left(7 a \right)}}{4 \sin^{4}{\left(\frac{7 a}{2} \right)}}\right) \sin^{2}{\left(\frac{7 a}{2} \right)}} & \text{otherwise} \end{cases}\right)$$
//              0                 for a mod pi = 0\   //                0                   for 7*a mod pi = 0\
||                                                |   ||                                                      |
||/     0       for a mod pi = 0                  |   ||/      0        for 7*a mod pi = 0                    |
|||                                               |   |||                                                     |
|||       /a\                                     |   |||       /7*a\                                         |
|<|  2*cot|-|                                     | + |<|  2*cot|---|                                         |
||<       \2/                        otherwise    |   ||<       \ 2 /                           otherwise     |
|||-----------     otherwise                      |   |||-------------      otherwise                         |
|||       2/a\                                    |   |||       2/7*a\                                        |
|||1 + cot |-|                                    |   |||1 + cot |---|                                        |
\\\        \2/                                    /   \\\        \ 2 /                                        /
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{2 \cot{\left(\frac{a}{2} \right)}}{\cot^{2}{\left(\frac{a}{2} \right)} + 1} & \text{otherwise} \end{cases} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{2 \cot{\left(\frac{7 a}{2} \right)}}{\cot^{2}{\left(\frac{7 a}{2} \right)} + 1} & \text{otherwise} \end{cases} & \text{otherwise} \end{cases}\right)$$
//              0                 for a mod pi = 0\   //                  0                     for 7*a mod pi = 0\
||                                                |   ||                                                          |
||                /a\                             |   ||                   /7*a\                                  |
||           2*cos|-|                             |   ||              2*cos|---|                                  |
||                \2/                             |   ||                   \ 2 /                                  |
||------------------------------     otherwise    |   ||--------------------------------------      otherwise     |
|
            
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{2 \cos{\left(\frac{a}{2} \right)}}{\left(\frac{\cos^{2}{\left(\frac{a}{2} \right)}}{\cos^{2}{\left(\frac{a}{2} - \frac{\pi}{2} \right)}} + 1\right) \cos{\left(\frac{a}{2} - \frac{\pi}{2} \right)}} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{2 \cos{\left(\frac{7 a}{2} \right)}}{\left(\frac{\cos^{2}{\left(\frac{7 a}{2} \right)}}{\cos^{2}{\left(\frac{7 a}{2} - \frac{\pi}{2} \right)}} + 1\right) \cos{\left(\frac{7 a}{2} - \frac{\pi}{2} \right)}} & \text{otherwise} \end{cases}\right)$$
//            0              for a mod pi = 0\   //               0                 for 7*a mod pi = 0\
||                                           |   ||                                                   |
||           /a   pi\                        |   ||            /  pi   7*a\                           |
||      2*sec|- - --|                        |   ||       2*sec|- -- + ---|                           |
||           \2   2 /                        |   ||            \  2     2 /                           |
||-------------------------     otherwise    |   ||-------------------------------      otherwise     |
|
            
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{2 \sec{\left(\frac{a}{2} - \frac{\pi}{2} \right)}}{\left(1 + \frac{\sec^{2}{\left(\frac{a}{2} - \frac{\pi}{2} \right)}}{\sec^{2}{\left(\frac{a}{2} \right)}}\right) \sec{\left(\frac{a}{2} \right)}} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{2 \sec{\left(\frac{7 a}{2} - \frac{\pi}{2} \right)}}{\left(1 + \frac{\sec^{2}{\left(\frac{7 a}{2} - \frac{\pi}{2} \right)}}{\sec^{2}{\left(\frac{7 a}{2} \right)}}\right) \sec{\left(\frac{7 a}{2} \right)}} & \text{otherwise} \end{cases}\right)$$
//              0                 for a mod pi = 0\   //                0                   for 7*a mod pi = 0\
||                                                |   ||                                                      |
||                /a\                             |   ||                 /7*a\                                |
||           2*csc|-|                             |   ||            2*csc|---|                                |
||                \2/                             |   ||                 \ 2 /                                |
||------------------------------     otherwise    |   ||----------------------------------      otherwise     |
|
            
$$\left(\begin{cases} 0 & \text{for}\: a \bmod \pi = 0 \\\frac{2 \csc{\left(\frac{a}{2} \right)}}{\left(\frac{\csc^{2}{\left(\frac{a}{2} \right)}}{\csc^{2}{\left(- \frac{a}{2} + \frac{\pi}{2} \right)}} + 1\right) \csc{\left(- \frac{a}{2} + \frac{\pi}{2} \right)}} & \text{otherwise} \end{cases}\right) + \left(\begin{cases} 0 & \text{for}\: 7 a \bmod \pi = 0 \\\frac{2 \csc{\left(\frac{7 a}{2} \right)}}{\left(\frac{\csc^{2}{\left(\frac{7 a}{2} \right)}}{\csc^{2}{\left(- \frac{7 a}{2} + \frac{\pi}{2} \right)}} + 1\right) \csc{\left(- \frac{7 a}{2} + \frac{\pi}{2} \right)}} & \text{otherwise} \end{cases}\right)$$
Piecewise((0, Mod(a = pi, 0)), (2*csc(a/2)/((1 + csc(a/2)^2/csc(pi/2 - a/2)^2)*csc(pi/2 - a/2)), True)) + Piecewise((0, Mod(7*a = pi, 0)), (2*csc(7*a/2)/((1 + csc(7*a/2)^2/csc(pi/2 - 7*a/2)^2)*csc(pi/2 - 7*a/2)), True))
Численный ответ [src]
sin(a) + sin(7*a)
sin(a) + sin(7*a)