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SSC CPO 2019 PYQ — Question 135

SSC CPO Tier I - 13th December 2019 - Shift 2 • Quantitative Aptitude • Q135

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If Cos2θ - Sin2θ = tan2θ, then which of the following is true?

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Correct answer: D

Explanation

The correct answer is Option 4 i.e. Cos2θ - Sin2θ= tan2θ

Application

Cos2θ - Sin2θ = tan2θ

let θ = 45

So,

Cos245  - Sin245

= (1/√2)2 - (1/√2)2

= 0

So, θ = 0

From option, we should check

θ = 45 & θ = 0:

Cos2θ - Sin2θ = tan2θ

⇒ Cos20 - Sin20 = tan245

⇒ 1 - 0 = 1

⇒ 1 = 1

Option 4 is correct.