MHT CET2009MathematicsCircle
If m₁ and m₂ are the slopes of tangents to the circle x²+y²=4 from the point (3,2) , then m₁-m₂ is equal to
Options
- A5 12
- B12 5
- C3 2
- D0
Correct answer
B. 12 5
Step-by-step solution
Equation of pair of tangents is S S₁=T² (x²+y²-4 )(9+4-4)=(3 x+2 y-4)² 5 y²+16 y-12 x y+24 x-52=0 m₁+m₂= -2 h b = 12 5 and m₁ m₂=0 Now, m₁-m₂= (m₁+m₂ )²-4 m₁ m₂ = ( 12 5 )²-0 = 12 5