# Thread: Determining Coordinates of Two points On a Circle

1. ## Determining Coordinates of Two points On a Circle

Assuming you have a circle with a radius of 2 with a line drawn exactly 1 unit away. What are the coordinates of the two points the line intersects. And how do I solve for it.

The picture explains it well

2. ## Re: Determining Coordinates of Two points On a Circle

Originally Posted by reteach
Assuming you have a circle with a radius of 2 with a line drawn exactly 1 unit away. What are the coordinates of the two points the line intersects. And how do I solve for it.

The picture explains it well

The equation of a circle with centre (0, 0) and radius r is $\displaystyle x^2+y^2=r^2$.

So find the equation of your circle and find the y values when x=1.

3. ## Re: Determining Coordinates of Two points On a Circle

Originally Posted by reteach
Assuming you have a circle with a radius of 2 with a line drawn exactly 1 unit away. What are the coordinates of the two points the line intersects. And how do I solve for it.

The picture explains it well
You are looking for the points $(1,p)$ on the circle.
Can you solve $1+p^2=4~?$

4. ## Re: Determining Coordinates of Two points On a Circle

Do you "see" a 30-60-90 right triangle?