Find tanØ if 9sin^2Ø - cos^2Ø =7
I have divided through with cos^2Ø
9tan^2Ø - 1 = 7sec^2Ø
But I am unsure on how to proceed from there.
The books answer gives it as: tanØ = ±2
Follow Math Help Forum on Facebook and Google+
$\sec^2(\theta) = 1 + \tan^2(\theta)$
make that substitution and then let $u=\tan(\theta)$
solve the resulting quadratic in $u$ and substitute $\tan(\theta)$ back in.