Question

given the function f(x)=-2x^2+4x-7, findv f(-4)
a.-55
b.-7
c.9
d.25

Answer 1

f(x) = 2x² +4x -7

f(-4) means we replace x by (-4) in the above equation:
f(-4) = 2(-4)² + 4(-4) -7
f(-4) = 2(16) -16 -7
f(-4) = 32 - 16 - 7 = 9 (answer c)