KCET2010MathematicsStraight Lines
Let P (-1,0), Q (0,0) and R=(3,3) be three points. The equation of the bisector of the angle PQR is
Options
- Ax- 3 y=0
- B3 x - y =0
- Cx + 3 y =0
- D3 x+y=0
Correct answer
D. 3 x+y=0
Step-by-step solution
array ll Given that, & P =(-1,0) and & Q =(0,0) & R =(3,3 3 ) array In AQR , aligned &= 3 3 3 &= 3 aligned aligned & & &= 60^ & &= 3 aligned Slope of line QR m ₁= 3 3 -0 3-0 = 3 m ₁= 3 Slope of line QP m ₂= 0-0 -1-0 =0 m ₂=0 Slope of line QP m ₂= 0-0 -1-0 =0 m ₂=0 Let the angle between PQR is , then aligned &= | m ₁- m ₂ 1+ m ₁ m ₂ | &= | 3 -0 1+0 |= 3 or - 3 & = 2 3 = 2 3 & [ ( 3 ) from figure ] aligned Hence, RQB = 2 = 2 6 = 3 So, the angle bisector making an angle with (+) ive x -axis, is 3 + 3 = 2 3 The equatio