# Thread: One real quick question

1. ## One real quick question

I encountered some problems for parabolas elipses conic equations etc that wanted, like, "The equation for right side of the graph"
or something like that...

The materials given to make the parabolas, elipses, did not have any restrictions on them, hence it would be a full normal equation and graph.

However, If they are asking for just partial of the graph, perhaps, does it imply that there should be restrictions? (Like X>1 for example), or is there a way to make an equation of a graph for only a section of it?

2. Originally Posted by 3deltat
I encountered some problems for parabolas elipses conic equations etc that wanted, like, "The equation for right side of the graph"
or something like that...
Say the problem says,
"Find the upper part of a circle at origin with radius one"

The full circle is described as,
x^2+y^2=1

But note when you solve for "y" you get:
y=+/-\sqrt{1-x^2}

Thus, y=sqrt{1-x^2} is the upper part.
And, y=-\sqrt{1-x^2} is the lower part.