# Homework Help: Changing equation to standard form

1. Sep 6, 2009

### renob

1. The problem statement, all variables and given/known data

Sketch the region in the xy-plane that is bounded between the graphs of the given functions. Find the points of intersection of the graphs.

1) y=x^2+2x+2

2)y=-x^2-2x+2

3. The attempt at a solution

I already completed the square for equation 1):
y=(x+1)^2+1

Im having trouble completing the square for the second equation because of the negative values. I tried factoring out the negative sign:

-(x^2+2x-2)

but that just makes the 2 negative.

How should I go about converting the second equation?

2. Sep 6, 2009

### renob

nevermind, i got it

3. Sep 6, 2009

### semc

Oh well from what i can see,-x^2-2x+2 = -(x^2+2x+2) +4. so....-x^2-2x+2=-(y)+4. If you can sketch the graph for the 1st one the second one shouldn't be a problem

4. Sep 7, 2009

### HallsofIvy

No, $-(x^2+ 2x- 2)= -x^2- 2+ 2$, not $x^2- 2x+ 2$.
$x^2- 2x+ 2= (x- 1)^2+ 1$.

5. Sep 7, 2009

### semc

hmm did i make a mistake somewhere? Where did the $x^2- 2x+ 2$ come from haha:

6. Sep 7, 2009

### renob

it comes out to be -(x+1)^2+3

7. Sep 7, 2009

### renob

I think you misread the second equation
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