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SSC CHSL 2023 PYQ — Question 67

SSC CHSL 2023 - 03 Aug 2023 - Shift 3 • Quantitative Aptitude • Q67

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Cos4 A - sin4 A is equal to:

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 1 - 2 sin2 A

Given that

Cos4 A - sin4 A

Formula used

sin2 A + cos2 A = 1 

Calculation

⇒ cos4 A - sin4 A

⇒ (cos2 A - sin2 A)(sin2 A + cos2 A) 

⇒ cos2 A - sin2 A 

⇒ 1 - sin2 A - sin2 A

⇒ 1 - 2 sin2 A