YOU ARE LEARNING:
Perpendicular lines are at right-angles to each other, and their equations are inter-linked, where the gradients are negative reciprocals of each other.
If two lines are perpendicular, then they are at right angles (90°) to one another.
Perpendicular lines have gradients which together multiply to make −1. We can also think that each gradient is the negative reciprocal of the other.
Which line below is perpendicular to y=4x−2?