A line passing through the point A(9,0) makes an angle of 30∘ with the positive direction of x-axis. If this line is rotated about A through an angle of 15∘ in the clockwise direction, then its equation in the new position is
(A)3−2y+x=9✓ Correct
(B)3−2x+y=9
(C)3+2x+y=9
(D)3+2y+x=9
Answer: (A)
Solution
The line initially makes 30∘ with the x-axis; rotating it 15∘ clockwise about A(9,0) gives a new inclination of 15∘, so slope =tan15∘=2−3.
Equation: y=(2−3)(x−9), i.e. 2−3y=x−9.
Since 2−31=2+3=−3−21, this is equivalent to 3−2y+x=9.
JEE Main · 2024 · 30 Jan 2024 · Shift 1 · Single correct option