Question

50 POINTS!!

Write an
equation for the circle with centre (0,0), if (12,5) lies on its circumference

Answer 1

x² + y² = 169

Explanation:

The equation of a circle centred at the origin is

x² + y² = r² ( r is the radius )

Given (12, 5 ) lies on the circumference , then the point will satisfy the equation.

Substitute (12, 5 ) into the equation

12² + 5² = r²

144 + 25 = r²

169 = r²

Then equation of circle is

x² + y² = 169