SSC CGL 2024 PYQ — Question 72

SSC CGL - 26 Sep 2024 - Shift 1 • Quantitative Aptitude • Q72

If A is an acute angle and tanA + cotA = 2, find the value of 7tan8A - 6cot8A + 8sec2A.

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 17.

tanA + cotA = 2

⇒ tanA + 1/tanA = 2

⇒ tan2A + 1 = 2tanA   [Multiplying both sides by tanA]

⇒ tan2A - 2tanA + 1 = 0

⇒ (tanA - 1)2 = 0

⇒ tanA = 1 = tan 45°

⇒ A = 45°

Now, 7tan8A - 6cot8A + 8sec2A = 7tan845° - 6cot845° + 8sec245°

= 7(1)8 - 6(1)8 + 8(√2)2

= 7 - 6 + 16

= 17

Therefore, the required value is 17.