Points for which $AX^2-BX^2$ is constant

712 Views Asked by At

My problem is from Israel Gelfand's Trigonometry textbook.

Page 9. Exercise 8: Two points, A and B, are given in the plane. Describe the set of points for which $AX^2-BX^2$ is constant.

I would appreciate some hints on how to approach the problem.

1

There are 1 best solutions below

7
On BEST ANSWER

We can use coordinate geometry, letting the two points be $(p,0)$ and $(-p,0)$, and grind it out. Not much grinding! If you prefer (I don't) you can let the points be $(a_1,a_2)$ and $(b_1,b_2)$.