Question

Find the equation of the line having inclination 135° and making X-intercept 7

Answer 1

Inclination of the line = θ = 135°

∴ slope of the line = m = tan θ

= tan 135°

= tan(180° – 45°)

= – tan 45°

= – 1

Since line has x-intercept 7, it is passing through the point (7, 0).

Now, equation of the line having slope m and passing through (x₁, y₁) is

y – y₁ = m(x – x₁)

∴ equation of the required line having slope – 1 and passing through (7, 0) is

y – 0 = – 1(x – 7)

∴ y = – x + 7

∴ x + y – 7 = 0.