Question

Which quadratic relation has a y-intercept of 8?

Answer 1

Answer:

y = 0.5 (x^2 -2x + 16) has a y-intercept of 8.

Step-by-step explanation:

The x-coordinate of every y-intercept is zero.  To determine which of the four quadratics given here has a y-intercept of 8, we need only substitute 0 for x in each; if the result is 8, we've found the desired quadratic.

O y = 0.5(x + 2)(x + 4) becomes y = 0.5(2)(4) = 4 (reject this answer)

O y = 0.5 (x - 2)(x + 8) becomes y = 0.5(-2)(8) = -8 (reject)

O y = 0.5(x2 -2x - 16) becomes y = 0.5(-16) = -8 (reject)

O y = 0.5 (x2 -2x + 16) becomes y = 0.5(16) = 8 This is correct; that '8' represents the y-intercept (0, 8).