How do I find the axis of the graph of the function $f (x) = 4 x^{2} + 8 x + 7$ $f(x)=4x^2+8x+7$ ?

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Answer 1 · 2015-10-13T17:38:33

By completing the square and equating the x value to 0.

So you first have to complete the square.

1) Divide whole equation by 4.

-> x^2 + 2x + 7/4

2) Complete the square.

-> 4( x^2+2x+1^2+7/4-1^2)
->4(x^2+1)+3/4

-> 4(x^2+1)+3

3) 4x+4=0
4x=-4
x=-1

How do I find the axis of the graph of the function f(x)=4x2+8x+7f(x)=4x^2+8x+7?