Question

Which of the following is an x-intercept of the graph of the function shown below?

f(x)=x² + 6x +9

Answer 1

B. x = -3

Explanation:

To find the x-intercept, substitute 0 for y and solve for x.

x-intercept(s): (-3,0)

Answer 2

Answer: Second option.

Explanation:

By defintion, a Quadratic function is a polynomial of degree 2 and it has the following form:

`f(x)=ax^2+bx+c`

Therefore, the function given is Quadratic. This is:

`f(x)=x^2 + 6x +9`

The steps to find the roots (or the x-intercepts) of the function, are:

1. You must substitute
`f(x)=0`:

`0=x^2 + 6x +9`

2. Now, you can factor the Quadratic equation. Choose two numbers whose sum is 6 and whose product is 9. Notice that:

`3+3=6\\3*3=9`

Therefore, you will get a "Double root".

4. So the solution is:

`(x+3)^2=0\\\\x=-3`