Q. 14 - Precalculus Enhanced with Graphing Utilities

Question

Use a calculator to evaluate the expression cos$\left(\frac{2\mathrm{\pi }}{5}\right)$ Round your answer to three decimal places.

Step-by-Step Solution

Answer

$\cos \left(\frac{2\mathrm{\pi }}{5}\right)\approx 0.309$

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

cos($\frac{2\mathrm{\pi }}{5}$)=0.3090169944

Step 3. Round the result to 3 decimal places

0.3090169944 $\approx$0.309