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The value of (cos25^(@))/(sin70^(@)sin8...

The value of `(cos25^(@))/(sin70^(@)sin85^(@))+(cos70^(@))/(sin 25^(@)sin85^(@))+(cos85^(@))/(sin25^(@)sin70^(@))` is

A

`1//2`

B

1

C

2

D

`3//2`

Text Solution

Verified by Experts

The correct Answer is:
C
Given expression `=(sin 50^(@)+sin 140^(@)+sin 170^(@))/(2sin 25^(@)sin 70^(@)sin 85^(@))`
`=(4)/(2)` (Using sin 2A + sin 2B + sin 2C =4 sin A sin B sin C, where `A+B+c=180^(@)`)
= 2
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