How do you write an equation with center (3,6), tangent to the x-axis?

1 Answer
Jul 18, 2016

The Question is not clear, but, I presume that what is reqd. is the eqn. of a circle having centre at (3,6) and the X-axis is tgt. to the reqd. circle.

x2+y26x12y+9+0

Explanation:

The Question is not clear, but, I presume that what is reqd. is the eqn. of a circle having centre at (3,6) and the X-axis is tgt. to the reqd. circle.

In that case, we know from Geometry that the dist. from the centre to a tgt. of a circle is equal to the radius of the circle.

Hence, r=radius= dist. from centre (3,6) to the X-axis
=y-co-ord. of C(3,6)=6.

Accordingly, the eqn. of the circle is :(x3)2+(y6)2=62, i.e.,

x2+y26x12y+9+0