Find $$\cos \left( { - \frac{{7\pi }}{2}} \right) = ?$$
A. $$\frac{1}{2}$$
B. 1
C. -1
Answer: Option D
Solution (By Examveda Team)
$$\eqalign{ & \cos \left( { - \frac{{7\pi }}{2}} \right) \cr & = \cos 7 \times \frac{{180}}{2} \cr & = \cos 630 \cr & = \cos \left( {2 \times 360 - 90} \right) \cr & = \cos 90 \cr & = 0 \cr} $$This Question Belongs to Arithmetic Ability >> Trigonometry
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