Question 139165
f(x)=x^2-4
f(x)=(x+2)(x-2)
x+2=0
x=-2 answer.
x-2=0
x=2 answer.
{{{ graph( 300, 200, -6, 5, -10, 10, x^2 -4) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, x^2 -4).