Question

In the coordinate plane, the x-axis (y=0) and y-axis (x=0) are perpendicular. The product of the slopes of two perpendicular lines is -1. Explain why this definition does not apply to the lines y=0 and x=0

Answer 1

Because the slope of the line x=0 is undefined, and the slope of the line y=0 is 0 and anything times 0 is 0