Question

Part of the graph of the function f(x) = (x - 1)(x + 7) is

shown below.
6
Which statements about the function are true? Select
three options.
The vertex of the function is at (-4,-15).
The vertex of the function is at (-3,-16).
The graph is increasing on the interval x > -3.
The graph is positive only on the intervals where x <-
7 and where
X > 1.
4
2+
-86 42
2
4
x
-2
The graph is negative on the interval x < 4.
-4
-6

Answer 1

B C D

Explanation:

In edg

Answer 2

In BOLD.

Explanation:

f(x) = (x - 1)(x + 7)

Convert to vertex form.

= x^2 + 6x - 7

= (x + 3)^2 - 9 - 7

= (x = 3)^2 - 16

So the vertex is at (-3, -16)

Also, as the vertex is a minimum the graph is increasing on interval x > -3.

From the graph we see:

The graph is positive on the interval

where x < -7 and x > 1.

- and negative where

-7 < x < 1.