# Thread: points of intersections, urgent!!!

1. ## points of intersections, urgent!!!

Determine the point(s) of intersection algebraically. Then verify your result numerically by creating a table of values for each equation.
y=2x^2
y=-2x^2+324
What I have so far is:
I set them equal to each other: 2x^2=-2x^2+324
Then I added 2x^2 to each side: 4x^2=324
Then I divided each side by 4: x^2=81
Then I took the square root of each side: x=9.
Where do I go from here...is that the only point of intersection???

2. Originally Posted by iheartthemusic29
Determine the point(s) of intersection algebraically. Then verify your result numerically by creating a table of values for each equation.
y=2x^2
y=-2x^2+324
What I have so far is:
I set them equal to each other: 2x^2=-2x^2+324
Then I added 2x^2 to each side: 4x^2=324
Then I divided each side by 4: x^2=81
Then I took the square root of each side: x=9.
Where do I go from here...is that the only point of intersection???
Hello,

that was a real near miss. You wrote:

Then I divided each side by 4: x^2=81
Then I took the square root of each side: x=9.
The correct answer is: | x | = 9 that means: x = 9 or x = -9.

Now plug in these values into one of the equations. I take the first one (it's easier to calculate):
x = 9: y = 2*(9)^2 = 162
x = -9: y = 2*(-9)^2 = 162

You have two points: (9, 162), (-9, 162)