if sinA=3/5 and cosB=5/13 and if A and B are two acute angles, find the exact value of the following functions.

Answer 1

I see no "following functions"

but to get you ready:

If sinA = 3/5, then cosA = 4/5, after constructing the triangle
if cosB = 5/13, then sinB = 12/13, again recognizing one of the standard
right-angled triangles

recall:
sin(A+B) = sinAcosB + cosAsinB
sin(A-B) = sinAcosB - cosAsinB

cos(A+B) = cosAcosB - sinAsinB
cos(A-B) = cosAcosB + sinAsinB

these are the most common, there are others, but I don't feel like
guessing.