Question

What are the x-intercepts of y=4x^2-16

Answer 1

(-2,0) and (2,0)

Explanation:

To find the x intercepts of a graph, you need to set the y to 0. This is because a graph only intersects the x axis at the line y=0. Hence:

`4x^2-16=0`

Factor:

`4(x^2-4)=0 \\\\4(x-2)(x+2)=0 \\\\x=2,-2`

The x intercepts are at (-2,0) and (2,0). Hope this helps!

Answer 2

The x intercepts are -2 and 2

Explanation:

y=4x^2-16

Set equal to zero to find the x intercepts

0 =4x^2-16

Factor

0 = 4(x^2 -4)

Factor again, noticing the difference of squares ( a^2 - b^2) = (a-b)(a+b)

0 = 4(x-2) (x+2)

Using the zero product property

0 = x-2 0 = x+2

x =2 x = -2

The x intercepts are -2 and 2