Question

The equation of a straight line which cuts off an intercept of 5 units on negative direction of y-axis and makes an angle of `120^@` with the positive direction ofx-axis is
A. `y+sqrt(3)x+5=0`
B. `y-sqrt(3)x+5=0`
C. `y+sqrt(3)x-5=0`
D. `y-sqrt(3)x-5=0`

Answer 1

Correct Answer - A
Slope of the required line, `m=tan 120^(@)=-sqrt(3)` (since it is making angle with positive direction of x-axis). Given, line cuts off an intercept of 5 units on negative direction of y-axis. This means line is intersecting y-axis at (0, -5)
`P=(0, -5)` and `m=-sqrt(3)`.
`:.` Equation of line is `y-(-5)=-sqrt(3) (x-0)`
`implies y+5=-sqrt(3)x`
`implies y+sqrt(3)x+5=0`.