Question

Two lines are perpendicular, and neither line is horizontal. Which of the following is not necessarily true of the lines?

Answer 1

Not necessarily true = May be false

Answer 2

You're solving it for 3 dimensions. Right?

Answer 3

I mean, both are simultaneously possible iff you're solving it in three dimensions.

Answer 4

A.
The slopes of the two lines are opposite reciprocals.
B.
One line must have a positive slope.
C.
The y-intercepts are the same.
D.
One line must have a negative slope.