Find the value of the derivative of the function at (╥, -1)

Function: g(t) = 2 + 3 cos t

My work:

Plugged in ╥ to t

2 + 3 cos (╥)

Then I turn it into g' (g prime)

The rule is usually multiply the exponent into the coefficient than minus one from the exponent.

For example y = 4x^2 + 4x + 1

y' = 8x + 4

Can anyone help me with 2 + 3 cos t.

Thanks!