Question

Is y=-2(x-5)(x-8) in standard form, vertex form, or intercept form?

Answer 1

Answer: Intercept form

Specifically it's the x intercepts that are easily determined.

The factor (x-5) leads to x-5 = 0 and then to x = 5

So because (x-5) is a factor, it means x = 5 is one of the x intercepts.

The other x intercept is x = 8 due to the factor (x-8)

We can't determine the y intercept with this method. To find the y intercept, plug in x = 0 to get y = -80

Side notes:

• Standard form of a parabola is y = ax^2 + bx + c
• Vertex form of a parabola is y = a(x-h)^2 + k where (h,k) is the vertex