Hey y'all!

Here is my integral:

$\displaystyle 75 \int sec^2x tanx dx$

The book does the substitution with $\displaystyle u = tanx$, $\displaystyle du = sec^2x dx$

I worked mine out before I looked at the answer, I changed everything to terms of sin and cos and worked it that way.

My answer:

$\displaystyle \frac{75}{2cos^2x} + C$

Book answer:

$\displaystyle \frac{75}{2} tan^2x + C$

Is my answer wrong?