Question

Which of the following is the graph of f(x) = x2 − 4x − 5?

graph of a quadratic function with a minimum at 2, negative 9 and x intercepts at negative 1 and 5

graph of a quadratic function with a minimum at 3, negative 4 and x intercepts at 1 and 5

graph of a quadratic function with a minimum at 2.5, negative 2.4 and x intercepts at 1 and 4

graph of a quadratic function with a minimum at negative 1.5, negative 6.2 and x intercepts at 1 and negative 4

(IF YOU NEED A PIC I WILL TRY!!!!)

Answer 1

Yeah uh I might need a picture

Answer 2

Okay one sec

Answer 3

To find where it intercepts the x axis you can factor this

\(f(x) = x^2 − 4x − 5\)

What are the multiples of 5?

Answer 4

1,5
5,1

Answer 5

Since 5 is negative you need a positive and a negative number
\((x+number) (x-number)\)

Which order of these numbers can add up to 4?

Answer 6

-4*

Answer 7

-5,1?

Answer 8

Right
So we have
\((x-5)(x+1)\)

To find the x-intercept (When the graph touches the x-axis) we set them equal to 0
\(x-5=0\) and \(x+1=0\)

Answer 9

Alright

Answer 10

So it would be 5,-1?

Answer 11

Yes, so x should be 5 and -1 when it touches the x axis

Answer 12

So graph A?

Answer 13

Yes

Answer 14

thanksssssssssss

Answer 15

Sure no problem!

Answer 16

You are one of the biggest help ever!