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°) =
⇒
⇒
⇒ θ = 45° satisfies the given equation,
So, cot(45°) = 1
Hence the value of cotθ is 1.