I am having extreme troubles with this section. My book is no help and my teacher is clueless. Any help with these problems would be greatly helpful. Also if possible please include reasons/rules and show work to help me better understand and learn. Thanks!

1). tan(Pi/2-x)cscx/csc^2x

2). 1+tanx/1+cotx

3). (sec^2x+csc^2x)-(tan^2x+cot^2x)

4). sec^2u-tan^2u/cos^2v+sin^2v