Question

What is the standard form of the equation of a circle with center (-3,6) and the radius is 4?

Answer 1

`(x+3)^2+(y-6)^2=16`

Explanation:

The standard form of the equation of a circle is.

`color(red)(|bar(ul(color(white)(a/a)color(black)((x-a)^2+(y-b)^2=r^2)color(white)(a/a)|)))`
where (a ,b) are the coords of centre and r, the radius.

Here the centre = (-3 ,6) → a =-3 and b = 6 , r = 4

Substituting these values into the standard equation

`rArr(x+3)^2+(y-6)^2=16`