Math Help - Simplify Trig

1. Simplify Trig

Please take a look at the attached question, thank you!

2. Recall that:
$\tan^2{x} = \sec^2{x} - 1$

Notice that $1-\sec^2{x} = -(\sec^2{x}-1)$

You end up with $-\cot{x}\sin{x}$...Remember that $\cot{x} = \frac{\cos{x}}{\sin{x}}$