# Intercept question (manipulating equations)

1. Jan 26, 2006

### mattmns

I saw this question yesterday.

Find the x and y intercepts of:

1/x = 1/y
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In this case are the intercepts undefined? Or can I cross multiply and get x = y, and then the intercepts are 0 and 0? Also, if I cannot cross multiply, or maniuplate the equation, does that mean that anytime you are not allowed to have x = 0, or y = 0 as values in the original equation, then the respective intercept is undefined?

Thanks!

2. Jan 26, 2006

### StatusX

The curve defined by that equation is the line y=x minus the point at the origin, so it has no intercepts. The equality simply doesn't hold (since the equation isn't well defined) at x=y=0.