Question

evaluate cos 1° cos 2° cos 3° ... cos 80°​

Answer 1

Answer:

Correct question cos1° cos2° cos3°...cos180°

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Step-by-step explanation:

$\sf\mathbb\color{brown} { LHS= cos {1}^{0} } \: cos {2}^{0} \: cos {3}^{0} ...cos {180}^{0} <$

$\sf\mathbb\color{red} {⟹cos1° cos2° cos3° ...cos90°... cos180° }$

$\sf\mathbb\color{red} {⟹cos1° cos2° cos3°... \times ... cos180°}$

$\sf\mathbb\color{red} {⟹0}$

$\sf\mathbb\color{red} {RHS}$

$\sf\mathbb\color{green} {Hence \: proved }$