Question

Find the equation of the line whose X-intercept is 3 and which is perpendicular to the line 3x − y + 23 = 0.

Answer 1

Slope of the line 3x − y + 23 = 0 is `(-3)/(-1)` = 3.

Since the required line is perpendicular to this line, the slope of the line is `-1/3`.

Since x-intercept of the line is 3, the line is passing through the point (3, 0).

∴ The equation of the required line is

y − 0 = `-1/3(x - 3)`

∴ 3y = − x + 3

∴ x + 3y = 3