Can someone give me the answer to this?

G(x) = 2 sin(2x - π) + 4. using complete sentences, explain how to find the minimum value for the function.

What number should be added to the expression x^2+3x+ in order to create a perfect square trinomial? 3/2 3 9/4 9

Subscriptions to a popular fashion magazine have gone down by a consistent percentage each year and can be modeled by the function y = 42,000(0.96)t. what does the value 42,000 represent in the function?