Question

How do you write the equation of the circle with center and radius (1,-3), 10?

Answer 1

`(x-1)^2+(y+3)^2=100`

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.

in this question a = 1 , b = -3 and r = 10

Substitute these values into the standard equation.

`(x-1)^2+(y-(-3))^2=10^2`

`rArr(x-1)^2+(y+3)^2=100" is the equation"`