I was told these 3 questions were crucial to the understanding of the topic, but I can't manage to work them out
(a) Find the exact value of sin-1(sin 5π/4)
(b) Why is the answer -π/4 and not 5π/4?
(a) Find sin(sin-1(-root2))
(b) Why is the answer undefined?
(a) Find tan(2(sin-1 5/13))