SSC CGL 2024 PYQ — Question 57

SSC CGL - 24 Sep 2024 - Shift 2 • Quantitative Aptitude • Q57

The value of (sinA + cosecA)2 + (cosA + secA)2 is :

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 7 + tan2A + cot2A

(sin A + cosec A)2 + (cos A + sec A)2

= (sin2A + 2sinA cosecA + cosec2A) + (cos2A + 2cosA secA + sec2A)

= (sin2A + 2sinA(1/sinA) + cosec2A) + (cos2A + 2cosA(1/cosA) + sec2A)

= (sin2A + 2 + cosec2A) + (cos2A + 2 + sec2A)

= (sin2A + cos2A) + 2 + 2 + cosec2A + sec2A

= 1 + 4 + cosec2A + sec2A   [∵ sin2A + cos2A = 1]

= 5 + cosec2A + sec2A

= 5 + (1 + cot2A) + (1 + tan2A)   [∵ sec2A = 1 + tan2A and cosec2A = 1 + cot2A]

= 5 + 1 + cot2A + 1 + tan2A

= 7 + tan2A + cot2A

Therefore, the required value is 7 + tan2A + cot2A.