Integrate sin(27t) (sec(cos 27t))^2 dt

[neosonata]

Homework Statement

Evaluate the indefinite integral.

∫sin(27t) (sec(cos 27t))^2 dt

Homework Equations

The Attempt at a Solution

u = cos27t
du = -27sin27t

dx = du / -27sin27t
∫sin(27t)*(sec(u))^2 * (du/-27sin27t)(-1/27) ∫(sec(u))^2 du

(-1/27)*tan(u)

= (-1/27)*tan(cos27t) + C ?

I am going on with this problem the wrong way?

 

[ehild]

It look s fine...

ehild

 

[neosonata]

Is it? Webassign is not accepting that answer for some reason.

 

[ehild]

Try to evaluate -1/27.

ehild