Given:
[tex]cos(4x)\text{ + cos}(2x)\text{ + cos}(3x)\text{ =0}[/tex]
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:
[tex]\begin{gathered} x\text{ = 2}\pi n\text{ + }\frac{2\pi}{3},\text{ n}\in\text{ Z} \\ x_1\text{ = 2}\pi n_1\text{ + }\frac{4\pi}{3}\text{ , n}_1\text{ }\in\text{ Z} \\ x_2\text{ = }\frac{\pi n_2}{3}\text{ + }\frac{\pi}{6},\text{ n}_2\text{ }\in\text{ Z} \end{gathered}[/tex]
