BITSAT2009MathematicsParabolaActual
The line (3 x-4 y+7=0 ) is rotated through an angle ( 4 ) in the clockwise direction about the point ((-1,1) ). The equation of the line in its new position is
Options
- A(7 y+x-6=0 )
- B(7 y-x-6=0 )
- C(7 y+x+6=0 )
- D(7 y-x+6=0 )
Correct answer
A. (7 y+x-6=0 )
Step-by-step solution
As ((-1,1) ) is a point on (3 x-4 y+7=0 ), the rotation is possible. Slope of the given line (=3 / 4 ). Slope of the line in its new position (= 3 4 -1 1+ 3 4 =- 1 7 ) The required equation is ( y -1=- 1 7 ( x +1) or 7 y + x -6=0 )