If (m, −3) is on a circle with center (2, −3) and radius 7, what is a value of m?
A. m= -5
B. m= 7
C. m= 2+- squareroot of 39
D. m= 5
We can use the equation of a circle to solve this :
(m - 2)^2 + ( -3 + 3)^2 = 7^2 simplify
(m - 2) + 0 = 49
(m - 2)^2 = 49 take both roots
m - 2 = ±7 add 2 to both sides
m = ±7 + 2 = 7 + 2 = 9 or -7 + 2 = -5
So.....A is correct
