Question

Find the x intercept of f(x)=4x^2-20

Answer 1

x int means y=0; this equals 0 when x = +-5 right?

Answer 2

I think so

Answer 3

how can we prove it?

Answer 4

idk

Answer 5

20 = 4x^2
5= x^2
x intercept is (square root of 5, 0)

Answer 6

is there a place in the equation to fit an x = -5 to see if this makes it equal zero?

Answer 7

sqrt(5) yes lol... good call