Each expression simplifies to a constant, a single trigonometric function or a power of a single trigonometric function. Use fundamental identities to simplify each expression.

1. $\displaystyle{(\sec (x))^2-1=}$
2. $\displaystyle{\tan (x) \cos (x)=}$
3. $\displaystyle{\sec (x) \cos (x)=}$
4. $\displaystyle{(\tan (x))^2 +\sin (x) \csc (x)=}$
5. $\displaystyle{\displaystyle\frac{\sin (x) \tan (x)}{\cos (x)}=}$