Question

If sinA=3/4, find the value of 2 cotA -1.​

Answer 1

Given:

$\sin A = \frac{3}{4}$

To Find:

Find the value of $2\cot A - 1$.

Solution:

Given, $\sin A = \frac{3}{4}$

Therefore, $\cos A = \sqrt{1 - \sin^2 A} = \sqrt{1 - (\frac{3}{4} )^2 } = \sqrt{\frac{16 - 9}{16} } = \frac{\sqrt{7} }{4}$

Now, $2\cot A - 1$

$=2 \frac{\cos A}{\sin A} - 1$

$= 2 \frac{\frac{\sqrt{7} }{4} }{\frac{3}{4} } - 1$

$= \frac{2\sqrt{7} }{3} - 1$

$= 0.7638$