1. ## integration problems

hi I have a few integration problems I'm not quite sure of and was wondering if anyone can help get to the integration stage...???

the integral of dx/(1-5x)

int of t^2(1+t^3)^1/3 dt

and int of sin^2(x) dx

any help would be ace!!

2. Originally Posted by blackout
hi I have a few integration problems I'm not quite sure of and was wondering if anyone can help get to the integration stage...???

the integral of dx/(1-5x)

int of t^2(1+t^3)^1/3 dt

and int of sin^2(x) dx

any help would be ace!!
for the first one, set u = 1-5x
for the second one, set u = 1+t^3

for the third one, remember this identity: $\cos (2x) = 1 - 2\sin^2 x$.. derive $\sin^2 x$