BITSAT2018MathematicsHyperbolaActual
If e 1 and e 2 are the eccentricities of a hyperbola 3 x 2 - 3 y 2 = 25 and its conjugate, then
Options
- Ae 1 2 + e 2 2 = 2
- Be 1 2 + e 2 2 = 4
- Ce 1 + e 2 = 4
- De 1 + e 2 = 2
Correct answer
B. e 1 2 + e 2 2 = 4
Step-by-step solution
Given equation can be written as x 2 - y 2 = 25 3 ∴   e 1 = 1 + b 2 a 2 = 1 + 1 = 2 The equation of conjugate hyperbola is - x 2 + y 2 = 25 3 ∴   e 2 = 1 + b 2 a 2 = 1 + 1 = 2 ∴   e 1 2 + e 2 2 = 2 2 + 2 2 = 4 Hence, e 1 2 + e 2 2 = 4 .