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प्रश्न
Evaluate the following :
`cos 19^@/sin 71^@`
उत्तर
Given that `cos 19^@/sin 71^@`
`=> cos 19/sin 71 = cos(90 - 71)/sin 71`
`=> cos 19/sin 71 = sin 71/sin 71`
`=> cos 19/sin 71 = 1`
Since `cos (90 - theta) = sin theta`
Therefore `cos 19^@/sin 71^@` = 1
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