Question

Find the y-intercept of the parabola

y=x^2-6x+8

Type a coordinate point like (9,-5) with no spaces.

Show your work.

Answer 1

Vertex is at (3,−1) ; y-intercept is at (0,8) and x-intercepts are at (2,0) and (4, 0)

We know the equation of parabola in vertex form is y = a(x - h)² + k where vertex is at (h,k). Here y = x² - 6x + 8 = (x - 3)² - 9 + 8 = (x - 3)² - 1 ∴ Vertex is at (3,-1) we find y-intercept by putting x = 0 in the equation. So y = 0 - 0 + 8 = 8 and x-intercept by putting y=0 in the equation. So x² - 6x + 8 = 0 or (x - 4)(x - 2) = 0 or x = 4; x = 2 graph{x^2-6x+8 [-20, 20, -10, 10]}