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The value of \( \Large \cos 1 ^{\circ} \cos 2 ^{\circ} \cos 3 ^{\circ} ....... \cos 100 ^{\circ} \) is equal to:

A) 1
B) -1
C) 0
D) none of these

Correct Answer:



C) 0

Description for Correct answer:
\( \Large \cos 1 ^{\circ} \cos 2 ^{\circ} \cos 3 ^{\circ} ....\cos 90 ^{\circ} .... \cos 100 ^{\circ} \)

= \( \Large \cos 1 ^{\circ} \cos 2 ^{\circ} \cos 3 ^{\circ} ....0 .... \cos 100 ^{\circ} = 0 \)

\( \Large [\because \cos 90 ^{\circ} = 0 ] \)

Part of solved Trigonometric ratio questions and answers : >> Elementary Mathematics >> Trigonometric ratio

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