1 / | | 1 | ---------- dx | 4*sin(2*x) | / 0
Integral(1/(4*sin(2*x)), (x, 0, 1))
/ | | 1 | ---------- dx | 4*sin(2*x) | /
1 ---------- 4*sin(2*x)
sin(2*x)
/sin(2*x)\ |--------| 1 \ 4 / ---------- = ---------- 4*sin(2*x) 2 sin (2*x)
sin(a)^2 + cos(a)^2 = 1
2 2 sin (2*x) = 1 - cos (2*x)
/sin(2*x)\ /sin(2*x)\ |--------| |--------| \ 4 / \ 4 / ---------- = ------------- 2 2 sin (2*x) 1 - cos (2*x)
u = cos(2*x)
/ | | /sin(2*x)\ | |--------| | \ 4 / | ------------- dx = | 2 | 1 - cos (2*x) | /
/ | | /sin(2*x)\ | |--------| | \ 4 / | ------------- dx = | 2 | 1 - cos (2*x) | /
/ | | -1 | ---------- du | / 2\ | 8*\1 - u / | /
/-1 \ |---| -1 \4*2/ / 1 1 \ ---------- = -----*|----- + -----| / 2\ 2 \1 - u 1 + u/ 8*\1 - u /
/ / | | | 1 | 1 | ----- du | ----- du / | 1 + u | 1 - u | | | | -1 / / = | ---------- du = - ----------- - ----------- | / 2\ 16 16 | 8*\1 - u / | /
= -log(1 + u)/16 + log(-1 + u)/16
u = cos(2*x)
/ | | 1 log(1 + cos(2*x)) log(-1 + cos(2*x)) | ---------- dx = - ----------------- + ------------------ + C0 | 4*sin(2*x) 16 16 | /
/ | | 1 log(tan(x)) | ---------- dx = C + ----------- | 4*sin(2*x) 8 | /
pi*I oo + ---- 16
=
pi*I oo + ---- 16
oo + pi*i/16
Estos ejemplos se pueden aplicar para introducción de los límites de integración inferior y superior.