SarkariPYQ

SSC CGL 2023 PYQ — Question 60

SSC CGL - 27 July 2023 - Shift 2 • Quantitative Aptitude • Q60

Back to paper

If 3x = sec A and 3x\frac{3}{x} = tan A then 9(x2−1x2)9\left(x^2 - \frac{1}{x^2}\right) is ______.

Show answer & explanation

Correct answer: C

Explanation

The correct answer is option 3 i.e. 1.

3x = sec A and 3/x ​= tan A

sec2 A = 1 + tan2 A

⇒ sec2 A - tan2 A = 1

Hence¸

⇒ (3x)2 = 1 + (3/x​)2

⇒ 9x2 = 1 + 9/x2

⇒ 9x2 - 9/x2  = 1 

⇒ 9(x2 - 1/x2 ) = 1