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©sin⁶theta + cos⁶theta= 1- 3sin ²theta × cos²theta |
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Answer» er Open in ANSWR app L.H.S. =sin θ+COS 6 θ =(sin 2 θ) 3 +(cos 2 θ) 3
Put sin 2 θ=a and cos 2 θ=B ∴ L.H.S. =a 3 +b 3
=(a+b) 3 −2ab(a+b) =(sin 2 θ−cos 2 θ) 3 −3sin 2 θcos 2 θ(sin 2 θ+cos 2 θ) =(1) 3 −3sin 2 θcos 2 θ[∵sin 2 θ+cos 2 θ=1] =1−3sin 2 θcos 2 θ = R.H.S. |
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