Question

Graph the function f(x) = (x + 1)(x - 5). Use the drop-

Answer 1

Answer:

3) (2,-9)

4) (0,-5)

5) (1,-8)

Step-by-step explanation:

3)

The vertex will occur between you x-intercepts.

You already found that happens at x=2.

To find the corresponding y-coordinate, replace x in

f(x)=(x+1)(x-5) with 2:

f(2)=(2+1)(2-5)

f(2)=(3)(-3)

f(2)=-9

So the vertex is (2,-9).

4)

The y-intercept is when x=0.

So in f(x)=(x+1)(x-5) replace x with 0:

f(0)=(0+1)(0-5)

f(0)=(1)(-5)

f(0)=-5

So the y-intercept is (0,-5).

5)

To find another point just plug in anything besides any x already used.

We preferably want to use a value of x that will keep us on their grid however far up,down,left, or right their grid goes out. So I'm going to choose something close to the vertex which is at x=2. Let's go with x=1.

So replace x in f(x)=(x+1)(x-5) with x=1:

f(1)=(1+1)(1-5)

f(1)=(2)(-4)

f(1)=-8

So another point to graph is (1,-8).