# Thread: Two lines meet. How do I find the x and y intercepts of this line on quadrant IV?

1. ## Two lines meet. How do I find the x and y intercepts of this line on quadrant IV?

The two lines (-4x) and (-2x^2+120x) meet. As you can see, one is a quadratic function and the other is a linear function.
I would like to know the x and y intercepts of quadrant IV.

I tried to set both functions equal to each other and calculated both coordinates of x and y using the quadratic formula. The results are (0,0) and (62,0). But these answers do not provide the other intercept that -2x^2+120x creates when meeting -4x in quadrant IV.

Can someone tell me how to find this said x and y coordinate?

2. ## Re: Two lines meet. How do I find the x and y intercepts of this line on quadrant IV?

This post is a mess.

You have a line and a parabola meeting. Not two lines. The term for a general line in space is called a curve.

I would like to know the x and y intercepts of quadrant IV.
What does this mean? Do you want the point $(x,y)$ of the intersection of these two curves?
The results you posted seem to indicate this though you got the second one wrong.

There are two points of intersection.

$(0,0)$ is clearly one of them

$-4x = -2x^2 + 120x$

$2x^2 = 124x$

if $x\neq 0$

$2x = 124$

$x = 62$

and plugging this into the linear function we get $y=-4\cdot 62 = -248$

So the point you're after is $(62, -248)$ which is indeed in the quadrant IV