Find an equation of the circle that has center (5,-4) and passes through (1,6)

Answer 1

the radius , per distance formula is, sqrt ( (5-1)^2 + (-4 - 6)^2)

= sqrt( 4^2 + (-10)^2)

= sqrt( 16 + 100)

= sqrt(116)

the equation is then (x-5)^2 + (y+4)^2 = 116