Question

What is the standard equation of a circle with center `(-2, 0)` and radius `4`?

Answer 1

`(x+2)^2+y^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 coordinates of the centre and r, the radius.

here a = -2 , b = 0 and r = 4

Substitute these values into the standard equation.

`(x-(-2))^2+(y-0)^2=4^2`

`rArr(x+2)^2+y^2=16" is the equation of the circle"`