There is a section on my worksheet that says

"Rewrite each expression in terms of the sine, cosine, or tangent using the addition and subtraction identities. Simplify each result."

I don't understand what I am suppose to do for that section.

first two problems:

sin(5pi/2 + t)

cos (pi/6-t)

and one more thing for another section i am suppose to be finding sin2t cos2t and tan2t

if sin t = 4/5, t in Q I

is this correct

sin2t = 8/5

cost2t = 6/5

tan2t = 8/3???

thanks in advance