Question

Find the value of cot35°15'.
(Refer the trigonometric table for the values)

• A. 1.2511
• B. 1.415
• C. 2.1121
• D. 1.6571

Answer 1

The correct option is B 1.415

We know that
cot35°15' = $\frac{1}{tan35°{15}^{\prime }}$ ... (i)
We can write,
35°15' = 35°12' + 3'
From the table we have, tan35°12' = 0.7054
Mean difference for 3′ = 13

tan35°12' = 0.7054
3′ = + 13 (Mean difference to be added for tan)
____________________
tan35°15' = 0.7067

Put the value of tan35°15' in equation (i)
cot35°15' = $\frac{1}{0.7067}$
cot35°15' = 1.4150