Question

How do you put a half-circle into equation form?

Answer 1

\[x = \sqrt{r^2 - y^2}\]
where r is the radius

Answer 2

thats for the upper half of the circle
it's the negative for the bottom half of the circle

Answer 3

So lets just say that the graph is on (9,0), (0,9), and (-9,0), and those are the dimensions of it. How can I put that into equation form?

Answer 4

the radius is 9
\[x = \sqrt{81 - y^2}\]

Answer 5

Thanks!

Answer 6

no problem