Question

Complete the square to find the center and radius of a circle x^2 + y^2 -10x + 8y - 8 =0

Answer 1

 

.hello :
an equation of the circle Center at the w(a,b) and   ridus : r is :

(x-a)² +(y-b)² = r² 

x² + y² -10x + 8y - 8 =0
(x²-10x)+(y²+8y) -8 = 0
(x²-2(5)(x)+5²)-5² +(y²+2(4)y +4²)-4² -8 =0
(x-2)² +(y-4)² -25-16-8 =0
(x-2)² +(y-4)² =7²
the center is : A( 2; 4) and   ridus is : 7