Calculus 1: Differentiation Rules (Video #9) | Math with Professor V

[@SteveSmith-th2wv]

At 21:30 it does not look like the normal line is perpendicular to the tangent line. However, if the scale on the x-axis was the same as the scale on the y-axis, the normal line would look perpendicular to the tangent line.

[@nickalexander2505]

is there a reason why the lines do not appear to be properly perpendicular? does it not matter what the angle of perpendicularity is or are we always trying to show perfectly perpendicular at a 90 degree angle?

[@mathwithprofessorv]

I didn’t scale the X and Y axes exactly the same, which is why the angle of intersection isn’t exactly 90°. But if your graph is labeled correctly, then this is usually an insignificant issue.