Question

Find an equation of the circle with center at ( 5 , 1 ) that is tangent to the y-axis in the form of ( x − A ) 2 + ( y − B ) 2 = C where A , B , C are constant

Answer 1

(x -5)² +(y -1)² = 25

Explanation:

The equation for a circle centered at (h, k) with radius r is ...

(x -h)² +(y -k)² = r²

Here, the radius is equal to the x-coordinate of the center, since you want the circle tangent to the y-axis. That means (h, k) = (5, 1) and r = 5. The equation you want is ...

(x -5)² +(y -1)² = 25