# How do you write an equation for a circle given center #(-sqrt13,42)# and passes through the origin?

##### 1 Answer

Oct 29, 2016

#### Explanation:

The general equation of a sphere is,

where the centre is at

So for this what we are missing is the radius but we have the centre and a point

the distance between the center and the point is,

Using Pythagoras's theorem this means that the radius is,

so back to the general equation,

sub in,