sec2 0 - 1 Simplify: csc2 0 - 1 tan2 0 O tan4 0 cot4 0 O 2 cot4 0cos 0 Simplify: 1 - sin 0 O sec 0 + tan 0 O csc 0 + tan 0 O sec 0 + cot 0 O sec 0 + csc 0tan 0 Simplify: sec 0 + 1 O sec 0 - 1 tan 0 o sec 0 + 1 tan 0 O sec 0 O tan 0 + 1 sec 0