Answer
$-7$
Work Step by Step
Need to solve $ 4 \csc 270^{\circ} +3 \cos 180^{\circ}$
In order to solve the given expression we can use Trigonometric table of angles.
But $\csc 270^{\circ} =\dfrac{1}{\sin 270^{\circ} }=\dfrac{1}{\sin (360^{\circ}-90^{\circ} )}=\dfrac{1}{\sin (-90^{\circ} )}=-\dfrac{1}{\sin (90^{\circ} )} =-1$
Therefore, we have:
$ 4 \csc 270^{\circ} +3 \cos 180^{\circ} = 4(-1) +3 (-1) =-4-3=-7$
