Question

If 3 cos A = 4 sin A, the value of cos A is $\frac{m}{5}$, m is

Answer 1

$3\cos A=4\sin A$
$\tan A=\frac{3}{4}$
$\tan A=\frac{P}{B}=\frac{3}{4}$
Now, Using Pythagoras Theorem,
$H^2=P^2+B^2$
$H^2=3^2+4^2$
$H=5$
Now, $\cos A=\frac{B}{H}=\frac{4}{5}$