NTA Abhyas JEE Main2020MathematicsHyperbolaPractice
A hyperbola has foci 4,2 , 2 , 2 and it passes through P 2 , 4 . The eccentricity of the hyperbola is
Options
- Atan 3 π 10
- Btan 5 π 12
- Ctan π 3
- Dtan 3 π 8
Correct answer
D. tan 3 π 8
Step-by-step solution
Let 4 , 2 = S 1 and 2 , 2 = S 2 and the eccentricity of the hyperbola is e , then S 1 S 2 = 2 a e and P S 1 - P S 2 = 2 a (where, 2 a is the length of the transverse axis) ⇒ e = S 1 S 2 P S 1 - P S 2 = 2 2 2 - 2 ⇒ e = 1 2 - 1 = 2 + 1 = tan ⁡ 3 π 8