sin (x) = -0.89 use the sine inverse
arcsin(-0.89) = x = -1.0973 + 2pi ≈ 5.1858 and x = pi + 1.0973 ≈ 4.2389
A ≈ 4.2389 rads and B ≈ 5.1858 rads
I doubt very much that felrose has any idea what you have done Chris.
I doubt if he/she is even interested.
He/she is not using us to learn he is just using us to do his/her homework.
No it is not!
I do not think it is what you do!
I think you try your best to learn from all the answers you are given!