So the problem is a verify the equation problem where the left side has to be made equal to the right : sin^{-1}* (4/5) - cos^{-1}* (12/13) = cos^{-1}* (56/65)

- My confusion come from two main things

1. I've never done a problem with negative 1 exponents and I can't find an example of one in my book

2. I've done a hundred of these verify problems but I've never come across one that is sin - cos = cos

Also my first time posting so I may have done something wring