Question

Another line “r” is perpendicular to the line 3y = 6x + 9. Find the gradient of the line "r" show your working

Answer 1

Line r has a gradient of -1/2

Explanation:

Perpendicular lines have a gradient of negative reciprocal to each other such that multiplying both the slopes give -1

=> Gradient of this line = 2

=> Gradient of line perpendicular to it =
`(-1)/(2)`

Multiplying both gradients:

=> 2 *
`(-1)/(2)`

=> -1

(SO They are perpendicular!)