(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

For the function f(x) = 1/4 (x=2)^2 - 4, i'm confused with regards to finding x & y intercepts.

2. Relevant equations

3. The attempt at a solution

You can work them out from the function in its current form, i think? For y-int, let x=0, which leaves (0,-3).

For x-nt, i done as follows;

1/4 (x+2)^2 = 4

(x+2)^2 = 16

x+2 = [tex]\pm[/tex] 4

x=2, x= -6

But then also one could use the quadratic formula, working from

1/4 (x^2 +4x +4) -4

1/4x^2 + x -3

Which gives intercepts 3/2, and -1/2

And also f(4x)= (x+2)^2 - 16

= x^2 + 4x - 12

=(x-2)(x+6)

4x=2, 4x= -6

x=1/2, x= -3/2

So, 3 different sets. What am i missing? I mean, i'm certain that the vertex lies at (-2,-4), so x=2, x=-6 must be the correct intercepts - but why are the others wrong?

Thanks.

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# Homework Help: Simple Function (x & y intercepts)

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