How do you write an equation for a circle given center (8,-9) and passes through (21,22)?
Please see the explanation for steps leading to the equation.
The standard form for the equation of a circle is:
We are given that the center point is
NOTE: One can write
To find the value of r, substitute the given point, 21 for x and 22 for y, into equation :
Equation  is the standard form for the circle.