Question

Solve in R 1) Cos(4x) + Cos (2x) + Cos (3x) = 0

Answer 1

Given:

`cos(4x)\text{ + cos}(2x)\text{ + cos}(3x)\text{ =0}`

To solve the problem, we have to plot the equation on a graph using a graphing tool.

The graph is shown below:

The solutions that can be summarized as:

`\begin{gathered} x\text{ = 2}\pi n\text{ + }(2\pi)/(3),\text{ n}\in\text{ Z} \\ x_1\text{ = 2}\pi n_1\text{ + }(4\pi)/(3)\text{ , n}_1\text{ }\in\text{ Z} \\ x_2\text{ = }(\pi n_2)/(3)\text{ + }(\pi)/(6),\text{ n}_2\text{ }\in\text{ Z} \end{gathered}`