Question
The angle between the pair of tangents drawn to the ellipse 3x2+ 2y2 = 5 from the point (1,2) is-
- tan–1
- tan–1(6
)
- tan–1
- tan–1 (12)
)
)
Hint:
find the equation of S by using
SS1=T2
The correct answer is: tan–1
Ѳ= tan-1(12/√5)
Equation of the curve :S = 3x2+2y2-5=0
S1= S(given point) = 3(1)2+2(2)2-5= 6
T1= 3x+4y-5=0
Use SS1=T2
=> 9x2-4y2-24xy+30x+40y-55=0
Here, a=9,b=-4 , h=-12
We know that
tan Ѳ=2√(h2-ab)/(a+b) = 12/√5
Ѳ= tan-1(12/√5)
use the equation of S to find the value of theta.
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