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

see the explanation

Explanation:

we know that

If two lines are perpendicular, then their slopes are opposite reciprocal (the product of their slopes is equal to -1)

In the coordinate plane, the x axis (y=0) and y axis (x=0) are perpendicular

however

this definition does not apply to the lines y=0 and x=0.

because

The slope of the horizontal line y=0 is equal to zero and the slope of the vertical line x=0 is undefined