Question

Prove that sin 72° cos 18°+ sin 18° cos 72°=1​

Answer 1

Answer:

Step-by-step explanation:

Answer 2

$\bf\blue{\underline{\boxed{Question}}}$

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$\small\tt{Prove\:\:}\\\\{\small\tt{Sin72°\:Cos18°\:+\:Sin18°\:Cos72\:=\:1}}$

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$\bf\blue{\underline{\boxed{Solution}}}$

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$\small\tt{Sin72°\:Cos18°\:+\:Sin18°\:Cos72\:=\:1}$

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$\small\tt\blue{\underline{\boxed{Formula}}}</p><p>\\\\\\{\small\tt\red{\:Sin(x+y)\:=\:Sinx\:cosy\:+\:cosx\:siny}}$

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$\small\tt{\rightarrow\:Sin(72\:+\:18)}$

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$\small\tt{\rightarrow\:Sin(90)}$

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$\small\tt\red{Note\:\rightarrow\:Value\:of\:sin\:90\:is\:1}$

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$\small\tt\red{\underline{\boxed{Sin(90)\:\:=\:\:1}}}$

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$\bf\blue{\underline{\boxed{Hope\:It\: Help\:You}}}$