Question

gerry thinks that the points (4,2) and (-1,4) form a line perpendicular to a line with slope 4. Do you agree? why or why not?

Answer 1

1st we need to know the slope of the line with the points (4, 2) and (-1, 4)

m = $\frac{4 - 2}{-1 - 4} = \frac{-2}{5}$

If the segments are perpendicular, then the slopes will multiply to -1
$4* \frac{-2}{5} = -\frac{8}{5} \neq -1$

Since the product is not -1 then the lines are not perpendicular.