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