Question

Find the value of cosec15°7'.
(Refer the trigonometric table for the values)

• A. 0.4512
• B. 0.8744
• C. 2.1134
• D. 3.8343

Answer 1

The correct option is D 3.8343

We know that
cosec15°7' = $\frac{1}{sin15°7^{\prime }}$ ... (i)
We can write,
15°7' = 15°6' + 1'
From the table we have, sin15°6' = 0.2605
Mean difference for 1′ = 3

sin15°6' = 0.2605
1′ = + 3 (Mean difference to be added for sine)
____________________
sin15°7' = 0.2608

Put the value of sin15°7' in equation (i)
cosec15°7' = $\frac{1}{0.2608}$
cosec15°7' = 3.8343