Question

How do you determine if a line is perpendicular, parallel, or neither?

Answer 1

Say we have the two lines:
`"Line 1":y=m_1x+c_1`
`"Line 2":y=m_2x+c_2`

If `m_1=m_2` then the lines are parallel, since they both have the same rate of change and therefore will never cross.

If `m_1m_2=-1` then they are perpendicular.