Here's the problem(s)

For #3 I need to find the cos graph equation here's what I got: shift to the right 2, Amplitude = 3, b = π/2 (pi/2)

equation: y=3cosπ/2(x-2)

I'm just not sure if i have it in the right format or if I'm even right

Attempt for #4 Amplitude=2 Shift left = 1 Shift up= 3

I'm just not sure if I am doing it right for both of them