Answer:
g(x) = 3sin(x + π/2) - 4
Explanation:
In a function
g(x) = Asin(x + C) + D
A is the vertical stretch,
C is the horizontal shift, it is positive to the left and negative to the right
D is the vertical shift, it is positive when it is up and it negative when it is down.
In this case, we want a vertical stretch by a factor of 3, so A = 3
A horizontal shift left π/2 units, so C = π/2
And a vertical shift of 4 units down, so D = -4.
Then, the equation is:
g(x) = 3sin(x + π/2) - 4