SSC CPO 2024 PYQ — Question 134

SSC CPO - 29 June 2024 - Shift 1 • Quantitative Aptitude • Q134

If sin4θ + cos4θ = 2sin2θcos2θ , 0°<θ<90° then find the value of cotθ.

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Correct answer: C

Explanation

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

Given that, sin4θ + cos4θ = 2sin2θcos2θ

Solving the given expression by value putting, 

Putting θ = 45°, sin4(45°) + cos4(45°) = 2sin2(45°)cos2(45°)

Now, sin(45°) = cos(45°) = 121 \over \sqrt{2}

⇒ (12)4+(12)4=2(12)2(12)2({1 \over \sqrt{2}})^4 + ({1 \over \sqrt{2}})^4 = 2({1 \over \sqrt{2}})^2({1 \over \sqrt{2}})^2

⇒ 12=12{1 \over 2} = { 1\over 2}  

⇒ θ = 45° satisfies the given equation,

So, cot(45°) = 1

Hence the value of cotθ is 1.