Q. 16 - Precalculus Enhanced with Graphing Utilities

Question

Use a calculator to evaluate the expression$cot\left(\frac{28\mathrm{\pi }}{9}\right)$ Round your answer to three decimal places. 

Step-by-Step Solution

Answer

$cot\left(\frac{28\mathrm{\pi }}{7}\right)\approx 2.747$

Step 1. Use of calculator

First we have to set the mode of calculator so that calculator can solve the Trigonometric functions. 

Step 2. Calculations

$$\begin{gathered} cot\left(\frac{28\mathrm{\pi }}{9}\right)=cot\left(3\mathrm{\pi }+\frac{\mathrm{\pi }}{9}\right)=cot\frac{\mathrm{\pi }}{9} \\ =\frac{1}{\tan {\displaystyle \frac{\mathrm{\pi }}{9}}}=2.7474774195 \end{gathered}$$

Step 3. Round the result to 3 decimal places

2.7474774195$\approx$2.747