Question

Determine the y-intercept of the following parabola:
y = (x - 3)(x + 7)

Answer 1

Answer:

The y intercept is -21

Step-by-step explanation:

y = (x - 3)(x + 7)

To find the y intercept, set x =0 and solve for y

y = (0-3) (x+7)

y = -3*7

y = -21

The y intercept is -21

Answer 2

Answer:

Step-by-step explanation:

For any function, its y-intercept will be the y value when x = 0.

You can simply plug in 0 for x in the function:

y = (0-3)(0+7)

  = (-3)(7)

  = -21

Therefore, the y-intercept of this parabola is -21.