How do you find the vertex and the intercepts for G(x) = x^2 + 4x?

1 Answer
Dec 10, 2017

Vertex is at (-2,-4) , y intercept is at (0,0) and
x intercepts are at
(0,0) and (-4,0)

Explanation:

G(x)=x^2+4x or G(x)=x^2+4x+4-4 or

G(x)=(x+2)^2-4 . Comparing with vertex form of

equation f(x) = a(x-h)^2+k ; (h,k) being vertex we find

here h=-2 , k=-4 :. Vertex is at (-2,-4) .

y intercept is found by putting x=0 in the equation

G(x)=x^2+4x or y=0 :. y intercept is (0,0)

x intercepts are found by putting y=0 in the equation

G(x)=y=x^2+4x or x^2+4x =0 or

x(x+4) =0 :. x=0 and x+4=0 :. x =-4

x intercepts are at (0,0) and (-4,0)

graph{x^2+4x [-10, 10, -5, 5]} [Ans]