Question

If $\cot A=\frac{8}{15}$ and $\sin A=\frac{15}{17}$ then, $\cos A=$

Answer 1

We know that $\cot x$ is $\cos x$ over $\sin x$ that is $\cot x=\frac{\cos x}{\sin x}$.

Here, it is given that $\sin A=\frac{15}{17}$ and $\cot A=\frac{8}{15}$, therefore,

$\cot A=\frac{\cos A}{\sin A}\Rightarrow \cos A=\sin A\times \cot A=\frac{15}{17}\times \frac{8}{15}=\frac{8}{17}$

Hence, $\cos A=\frac{8}{17}$.