Which point is an x-intercept of the quadratic function f(x)=(x-4)(x+2)

x = - 2 or x = 4

Step-by-step explanation:

To find the x- intercepts let f(x) = 0, that is

(x - 4)(x + 2) = 0

Equate each factor to zero and solve for x

x - 4 = 0 ⇒ x = 4

x + 2 = 0 ⇒ x = - 2

The x- intercepts are at x = - 2, x = 4

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i