Question

How do you write the standard from of the equation of the circle given center at (-2,5) and radius of 5?

Answer 1

`x^2+y^2+4x-10y+4=0.`

Explanation:

If the centre & radius of circle are `(h,k) & r`, then, its eqn. is :`(x+h)^2+(y-k)^2=r^2`

Hence, the reqd. eqn. is `(x+2)^2+(y-5)^2=5^2.` Simplifying, it becomes,
`x^2+y^2+4x-10y+4=0.`