Question

Determine whether the graphs of y =-9x+12 and y=1/3x-12 are parallel, perpendicular, coincident

Answer 1

1) graphs y = -9x + 12 and y = 1/3x - 12 are not coincident.

2) The graphs are not parallel, because the angular coefficients are not equal

3) The condition of perpendicularity:

$k_1\cdot k_2=-1$, where $k_1=-9;~~~ k_2=\frac{1}{3}$

$(-9)\cdot\frac{1}{3}=-3\ne -1$ - not perpendicular