Question

Using intercepts and the maximum, find an equation for the graph shown.

Answer 1

Answer:

It's D

Step-by-step explanation:

The x intercepts ( the zeroes) are -1 and 3 so we can write it as

f(x) = a(x + 1)(x - 3)   where a is some constant.

The y intercept is at  (0, 9) so substituting:-

9 = a *(0 + 1) * (0 -3)

9 = -3a

a = -3 so we have:-

f(x) = -3(x  + 1)(x - 3)

= -3(x^2  - 2x - 3)

= -3x^2 + 6x + 9.  (answer)

Answer 2

Answer:

f(x) = -3x2 + 6x + 9

x-intercepts: x = -1 and x = 3

y-intercept: y = 9

maximum value: y = 12