What is the vertex of f(x) = 5x^2 + 20x - 16?
A.(-2,-16)
B. (4,2)
C. (-2,-36)
D. (2,16)
First, we need to find the x-coordinate of the vertex using the formula x = -b/(2a), where a = 5 and b = 20 for the given function f(x) = 5x^2 + 20x - 16.
x = -20/(2*5) = -20/10 = -2
Now, plug this x-coordinate back into the original function to find the y-coordinate:
f(-2) = 5(-2)^2 + 20(-2) - 16
f(-2) = 5(4) - 40 - 16
f(-2) = 20 - 40 - 16
f(-2) = -36
Therefore, the vertex of the function f(x) = 5x^2 + 20x - 16 is (-2, -36).
C. (-2, -36)