Question

find the slope of the line perpendicular to each given line y=2x-1

Answer 1

Perpendicular means it has a negative reciprocal of the slope you are given.

The slope in this problem is 2 (the number in front of the x when you have y = )

so the negative reciprocal is -1/2 because 2 is like 2/1

Answer 2

but why is it
not just 1/2

Answer 3

because it is always the negative of that or the opposite of that....

Answer 4

If you really understand graphs and can visualize two graphs that meet at 90 degree angles, you should be able to see that one of the lines needs to be a positive slope and one of them needs to be a negative slope.