Integration Homework Help: Solving Integral [sec(x^2)/81 + tan(x^2)]

[zingoria]

Homework Statement

Integral [sec(x^2)/ 81 + tan (x^2)]

Homework Equations

sinx^2 + cos x^2=1
sec= 1/cos

The Attempt at a Solution

integral[ 1/81cos (x^2) + 81(sin(x^2)/cos(x^2))]
= 1/81 integral [1/ 1/cos(x^2)]= 1/8 integral[cos(x^2)]
= 1/8 sin(x^2)
This was my answer. But this is not right according to multiple choice quiz. Please let me know how to do this problem.

thanks.

 

[Gib Z]

Something makes me think finding the anti derivative won't be easy. But since this is a Multiple choice question, can you see how we can test each of those answers?