College Algebra Word problem

Question

Find the maximum value of the quadratic function.

y = −3x² − 6x − 24

Answer 1

take the derivative, set = 0, solve for x, plug back into the original equation, to get y=-15

another way to do this is use the quadratic formula but ignore the + and - square root of b^2-4ac

-b/2a = 6/-6 = -1. x=-1 at the maximum value of y

plug x=-1 into the original equation y=-3(-1)^2-6(-1)-24= -3+6-24 = -21