Question

What is the axis of symmetry of the function f(x)=−(x+9)(x−21)?

Answer 1

c

Explanation:

lol just took the quiz x=6

Answer 2

Therefore the given equation is a parabolic equation with vertex at (6,255) and the axis of symmetry is given by x = 6.

Explanation:

i) f(x) = -(x+9)(x-21)

ii) therefore y = f(x) = -
`x^(2)` + 12x + 189 = - (
`x^(2)` - 12x +36) + 36 + 189

iii) therefore y = f(x) = -
`(x-6)^(2)`+ 225

iv) when x = 6 then y = 255

Therefore the given equation is a parabolic equation with vertex at (6,255) and the axis of symmetry is given by x = 6.