1 / | | 1 | 1*------ dx | cos(x) | / 0
/ | | 1 | 1*1*------ dx | cos(x) | /
1 1*------ cos(x)
cos(x)
1 1*cos(1*x) 1*------ = ---------- cos(x) 2 cos (1*x)
sin(a)^2 + cos(a)^2 = 1
2 2 cos (x) = 1 - sin (x)
1*cos(1*x) 1*cos(1*x) ---------- = ------------- 2 2 cos (1*x) 1 - sin (1*x)
u = sin(x)
/ | | 1*cos(1*x) | ------------- dx | 2 = | 1 - sin (1*x) | /
/ | | 1*cos(1*x) | ------------- dx | 2 = | 1 - sin (1*x) | /
/ | | 1*cos(1*x) | ------------- du | 2 | 1 - sin (1*x) | /
1*cos(1*x) 1*1 / 1 1 \ ------------- = ---*|----- + -----| 2 2 \1 - u 1 + u/ 1 - sin (1*x)
/ / | | | 1 | 1 | ----- du | ----- du / | 1 + u | 1 - u | | | | 1*cos(1*x) / / = | ------------- du = ----------- + ----------- | 2 2 2 | 1 - sin (1*x) | /
= u*cos(x)/(1 - sin(x)^2)
u = sin(x)
/ | | 1 log(1 + sin(x)) log(-1 + sin(x)) | 1*1*------ dx = --------------- - ---------------- + C0 | cos(x) 2 2 | /
/ | | 1 log(1 + sin(x)) log(-1 + sin(x)) | 1*------ dx = C + --------------- - ---------------- | cos(x) 2 2 | /
log(1 + sin(1)) log(1 - sin(1)) --------------- - --------------- 2 2
=
log(1 + sin(1)) log(1 - sin(1)) --------------- - --------------- 2 2
Данные примеры также можно применять при вводе верхнего и нижнего предела интегрирования.