Question

Find the x-intercept of the parabola with vertex (4 -1) and y-intercept (0 15)

Answer 1

Equation of the parabola in vertex form is y = (x - 4)^2 - 1
y = x^2 - 8x + 16 - 1
y = x^2 - 8x + 15
The x-intercepts are the values of x when y = 0.
x^2 - 8x + 15 = 0
(x - 3)(x - 5) = 0
x = 3 and x = 5
Therefore, x-intecepts are 3 and 5.