Question

= If sin 2A = cos (A - 18°) is true, then A is equal to :​

Answer 1

sin2A=cos(A−18

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)

⟹cos(90

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−2A)=cos(A−18

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)

⟹90

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−2A=A−18

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⟹2A+A=90

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+18

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⟹3A=108

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⟹A=36

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