I have a project due tom and I have to answer 16 problems and I need help with 3

1.TANx(COTx+TANx)=SEC^2x
2.SINx(1+COT^2x)=CSCx
3.TANxCOSx=COTx(SECx-COSx)


Any help will be greatly appreciated thanksssssssss

1. (left) Expand, and remember one identity.

2. (left) Substitute cot^2x by 1 + csc^2x and then expand.

3. (right) Express all in terms of cos and sin. Combine fractions, use the Pythagorean idendity and simplify. You'll see that there is something wrong.