Answer :

Answer:

0.51508

Explanation:

Since you didn't post the picture of the graph, im assuming the circle is on the middle of the graph i.e. the center at (0,0)

A unit circle means that the the radius of the circle is 1, therefore the highest y value would be 1, and the lowest y value would be -1.

The equation of a circle is x^2 + y^2 = r^2, r being the radius. Since the radius of a unit circle is 1, the equation would be x^2 + y^2 = 1

So to find y, just plug in the x.

(6/7)^2 + y^2 = 1

1 - (6/7)^2 = y^2

sqrt(1-(6/7)^2) = 0.51508

If the center of the circle is not (0,0), the equation would be (x-h)^2 + (y-k)^2 = r^2, where (h,k) is the coordinate of the center.

For further question, don't hesitate to comment. I would appreciate it if you would notify me if the circle was indeed in the center or not.

Hope that answers it.