If a2sec2x - b2tan2x = c2 then, find the the value of sec2x + tan2x. (b2 ≠ a2) :
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. (b2 + a2 - 2c2)/(b2 - a2).
a2sec2x - b2tan2x = c2 .....(1)
we know,
⇒ sec2x - tan2x = 1
⇒ tan2x = sec2x - 1 .....(2)
From (1) and (2), we get
⇒ sec2x = (c2 - b2)/(a2 - b2)
⇒ tan2x = (c2 - a2)/(a2 - b2)
⇒ sec2x + tan2x = (c2 - b2 + c2 - a2)/(a2 - b2) = (b2 + a2 - 2c2)/(b2 - a2)