The line Ax+By=C (with C nonzero) is tangent to some circle centered at the origin.

What is the radius of that circle in terms of A, B, and C?

What is the point of tangency in terms of A, B, and C?

(In reply to

solution for part 2; outline for part 1 by Charlie)

Given Charlie's start, the rest can be done in my head.

The point of tangency simplifies to

**a*c / (a^2+b^2), b*c / (a^2+b^2)**

**The radius is therefore**

**sqrt(****a^2+b^2)***** c/****(a^2+b^2)**

**= **** c/sqrt(****a^2+b^2)**

*Edited on ***January 5, 2017, 8:26 am**