Question 28
Coordinate GeometryA straight line makes an angle of 30° with the positive x-axis and cuts the y-axis at y = 5. Find the equation of the straight line.
- A.√3y = x + 5√3
- B.√3y = −x + 5√3
- C.y = x + 5
- D.y = (1/10)x + 5
Show the answer and explanation
Answer: A (√3y = x + 5√3)
Explanation
The gradient is tan 30° = 1/√3 and the intercept is 5, so y = x/√3 + 5. Multiplying by √3 gives √3y = x + 5√3.