Question

Find the value of x so that the line passing through (3, 4) and (x, 5) makes an angle 135° with positive direction of X-axis.

Answer 1

Slope of the line which makes an angle 135° with X-axis,
m = tan 135°
= -1.
Also slope m = `(5 - 4)/(x - 3) = (1)/(x - 3)`
Then, `(1)/(x - 3)` = -1
⇒ x - 3 = -1
∴ x = 2.