Question

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

Answer 1

concept :-

Let, m and n be the gradients/slopes of two perpendicular lines

then, m×n = -1

& equation of line can be written as

y = mx + c , where m = gradient of line and c = y-intercept

Solution:-

Given equation of line is-

3y = 6x + 9

or, y = 2x + 3

gradient of above line (m) = 2

Let n be the gradient of line r

Lines are perpendicular

therefore, m× n = -1

or, n = (-1)/m

or, n= (-1)/2 = -0.5

Hence, Gradient of line r is -1/2.