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cos(7*x) если x=-3

Выражение, которое надо упростить:

Решение

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

            
$$\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\cos{\left(7 x \right)} & \text{otherwise} \end{cases} & \text{otherwise} \end{cases}$$
/      1         for 7*x mod 2*pi = 0
|                                    
|         1                          
|-1 + ---------                      
|        2/7*x\                      
|     tan |---|                      
<         \ 2 /                      
|--------------       otherwise      
|        1                           
|1 + ---------                       
|       2/7*x\                       
|    tan |---|                       
\        \ 2 /                       
$$\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\frac{-1 + \frac{1}{\tan^{2}{\left(\frac{7 x}{2} \right)}}}{1 + \frac{1}{\tan^{2}{\left(\frac{7 x}{2} \right)}}} & \text{otherwise} \end{cases}$$
/                                  /pi      \           
|             0                for |-- + 7*x| mod pi = 0
|                                  \2       /           
<                                                       
|                  /pi   7*x\                           
|(1 + sin(7*x))*cot|-- + ---|          otherwise        
\                  \4     2 /                           
$$\begin{cases} 0 & \text{for}\: \left(7 x + \frac{\pi}{2}\right) \bmod \pi = 0 \\\left(\sin{\left(7 x \right)} + 1\right) \cot{\left(\frac{7 x}{2} + \frac{\pi}{4} \right)} & \text{otherwise} \end{cases}$$
       2/  pi   7*x\
    cos |- -- + ---|
        \  2     2 /
1 - ----------------
          2/7*x\    
       cos |---|    
           \ 2 /    
--------------------
       2/  pi   7*x\
    cos |- -- + ---|
        \  2     2 /
1 + ----------------
          2/7*x\    
       cos |---|    
           \ 2 /    
$$\frac{1 - \frac{\cos^{2}{\left(\frac{7 x}{2} - \frac{\pi}{2} \right)}}{\cos^{2}{\left(\frac{7 x}{2} \right)}}}{1 + \frac{\cos^{2}{\left(\frac{7 x}{2} - \frac{\pi}{2} \right)}}{\cos^{2}{\left(\frac{7 x}{2} \right)}}}$$
          2/7*x\    
       sec |---|    
           \ 2 /    
1 - ----------------
       2/  pi   7*x\
    sec |- -- + ---|
        \  2     2 /
--------------------
          2/7*x\    
       sec |---|    
           \ 2 /    
1 + ----------------
       2/  pi   7*x\
    sec |- -- + ---|
        \  2     2 /
$$\frac{- \frac{\sec^{2}{\left(\frac{7 x}{2} \right)}}{\sec^{2}{\left(\frac{7 x}{2} - \frac{\pi}{2} \right)}} + 1}{\frac{\sec^{2}{\left(\frac{7 x}{2} \right)}}{\sec^{2}{\left(\frac{7 x}{2} - \frac{\pi}{2} \right)}} + 1}$$
       2/pi   7*x\
    csc |-- - ---|
        \2     2 /
1 - --------------
         2/7*x\   
      csc |---|   
          \ 2 /   
------------------
       2/pi   7*x\
    csc |-- - ---|
        \2     2 /
1 + --------------
         2/7*x\   
      csc |---|   
          \ 2 /   
$$\frac{1 - \frac{\csc^{2}{\left(- \frac{7 x}{2} + \frac{\pi}{2} \right)}}{\csc^{2}{\left(\frac{7 x}{2} \right)}}}{1 + \frac{\csc^{2}{\left(- \frac{7 x}{2} + \frac{\pi}{2} \right)}}{\csc^{2}{\left(\frac{7 x}{2} \right)}}}$$
/                        /pi      \           
|        0           for |-- + 7*x| mod pi = 0
|                        \2       /           
|                                             
|      /pi   7*x\                             
< 2*cot|-- + ---|                             
|      \4     2 /                             
|------------------          otherwise        
|       2/pi   7*x\                           
|1 + cot |-- + ---|                           
\        \4     2 /                           
$$\begin{cases} 0 & \text{for}\: \left(7 x + \frac{\pi}{2}\right) \bmod \pi = 0 \\\frac{2 \cot{\left(\frac{7 x}{2} + \frac{\pi}{4} \right)}}{\cot^{2}{\left(\frac{7 x}{2} + \frac{\pi}{4} \right)} + 1} & \text{otherwise} \end{cases}$$
/                1                  for 7*x mod 2*pi = 0
|                                                       
|  -2 - 2*cos(14*x) + 4*cos(7*x)                        
<---------------------------------       otherwise      
|                                2                      
|1 - cos(14*x) + 2*(1 - cos(7*x))                       
\                                                       
$$\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\frac{4 \cos{\left(7 x \right)} - 2 \cos{\left(14 x \right)} - 2}{2 \left(- \cos{\left(7 x \right)} + 1\right)^{2} - \cos{\left(14 x \right)} + 1} & \text{otherwise} \end{cases}$$
/       1          for 7*x mod 2*pi = 0
|                                      
|         2                            
|      sin (7*x)                       
|-1 + -----------                      
|          4/7*x\                      
|     4*sin |---|                      
<           \ 2 /                      
|----------------       otherwise      
|        2                             
|     sin (7*x)                        
|1 + -----------                       
|         4/7*x\                       
|    4*sin |---|                       
\          \ 2 /                       
$$\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\frac{-1 + \frac{\sin^{2}{\left(7 x \right)}}{4 \sin^{4}{\left(\frac{7 x}{2} \right)}}}{1 + \frac{\sin^{2}{\left(7 x \right)}}{4 \sin^{4}{\left(\frac{7 x}{2} \right)}}} & \text{otherwise} \end{cases}$$
/                  1                    for 7*x mod 2*pi = 0
|                                                           
|/      1         for 7*x mod 2*pi = 0                      
||                                                          
||        2/7*x\                                            
<|-1 + cot |---|                                            
|<         \ 2 /                             otherwise      
||--------------       otherwise                            
||       2/7*x\                                             
||1 + cot |---|                                             
\\        \ 2 /                                             
$$\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\frac{\cot^{2}{\left(\frac{7 x}{2} \right)} - 1}{\cot^{2}{\left(\frac{7 x}{2} \right)} + 1} & \text{otherwise} \end{cases} & \text{otherwise} \end{cases}$$
/          1            for 7*x mod 2*pi = 0
|                                           
|           2/7*x\                          
|        cos |---|                          
|            \ 2 /                          
|-1 + ----------------                      
|        2/  pi   7*x\                      
|     cos |- -- + ---|                      
<         \  2     2 /                      
|---------------------       otherwise      
|           2/7*x\                          
|        cos |---|                          
|            \ 2 /                          
| 1 + ----------------                      
|        2/  pi   7*x\                      
|     cos |- -- + ---|                      
\         \  2     2 /                      
$$\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\frac{\frac{\cos^{2}{\left(\frac{7 x}{2} \right)}}{\cos^{2}{\left(\frac{7 x}{2} - \frac{\pi}{2} \right)}} - 1}{\frac{\cos^{2}{\left(\frac{7 x}{2} \right)}}{\cos^{2}{\left(\frac{7 x}{2} - \frac{\pi}{2} \right)}} + 1} & \text{otherwise} \end{cases}$$
/          1            for 7*x mod 2*pi = 0
|                                           
|        2/  pi   7*x\                      
|     sec |- -- + ---|                      
|         \  2     2 /                      
|-1 + ----------------                      
|           2/7*x\                          
|        sec |---|                          
<            \ 2 /                          
|---------------------       otherwise      
|        2/  pi   7*x\                      
|     sec |- -- + ---|                      
|         \  2     2 /                      
| 1 + ----------------                      
|           2/7*x\                          
|        sec |---|                          
\            \ 2 /                          
$$\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\frac{-1 + \frac{\sec^{2}{\left(\frac{7 x}{2} - \frac{\pi}{2} \right)}}{\sec^{2}{\left(\frac{7 x}{2} \right)}}}{1 + \frac{\sec^{2}{\left(\frac{7 x}{2} - \frac{\pi}{2} \right)}}{\sec^{2}{\left(\frac{7 x}{2} \right)}}} & \text{otherwise} \end{cases}$$
/         1           for 7*x mod 2*pi = 0
|                                         
|          2/7*x\                         
|       csc |---|                         
|           \ 2 /                         
|-1 + --------------                      
|        2/pi   7*x\                      
|     csc |-- - ---|                      
<         \2     2 /                      
|-------------------       otherwise      
|          2/7*x\                         
|       csc |---|                         
|           \ 2 /                         
| 1 + --------------                      
|        2/pi   7*x\                      
|     csc |-- - ---|                      
\         \2     2 /                      
$$\begin{cases} 1 & \text{for}\: 7 x \bmod 2 \pi = 0 \\\frac{\frac{\csc^{2}{\left(\frac{7 x}{2} \right)}}{\csc^{2}{\left(- \frac{7 x}{2} + \frac{\pi}{2} \right)}} - 1}{\frac{\csc^{2}{\left(\frac{7 x}{2} \right)}}{\csc^{2}{\left(- \frac{7 x}{2} + \frac{\pi}{2} \right)}} + 1} & \text{otherwise} \end{cases}$$
Piecewise((1, Mod(7*x = 2*pi, 0)), ((-1 + csc(7*x/2)^2/csc(pi/2 - 7*x/2)^2)/(1 + csc(7*x/2)^2/csc(pi/2 - 7*x/2)^2), True))