Question

Find the exact value of each expression. Do not use a calculator.

$4\sin 90°-3\tan 180°$

Short answer

The exact value of$4\sin 90°3\tan 180°=4$

Step-by-step solution

Step 1. Given information

$4\sin 90°-3\tan 180°$

Step 2. Solution

$$\begin{gathered} \sin 90°=1 \\ \tan 180°=\frac{\sin 180°}{\cos 180°}=\frac{0}{-1}=0 \\ \tan 180°=0 \\ \mathrm{Putting}\mathrm{the}\mathrm{values}\mathrm{in}\mathrm{the}\mathrm{given}\mathrm{expression}\mathrm{we}\mathrm{get}, \\ (4\times 1)-(3\times 0)=4 \\ \mathrm{So}, \\ 4\sin 90°3\tan 180°=4 \end{gathered}$$