Question Number 165370 by daus last updated on 31/Jan/22
Commented by daus last updated on 31/Jan/22
$${solve}\:{x} \\ $$
Answered by Ar Brandon last updated on 31/Jan/22
$$\mathrm{cos}\left(\mathrm{3}{x}+\mathrm{60}°\right)=\mathrm{sin}\left(\mathrm{3}{x}\right) \\ $$$$\mathrm{cos}\left(\mathrm{3}{x}+\frac{\pi}{\mathrm{3}}\right)=\mathrm{cos}\left(\frac{\pi}{\mathrm{2}}−\mathrm{3}{x}\right) \\ $$$$\mathrm{3}{x}+\frac{\pi}{\mathrm{3}}=\frac{\pi}{\mathrm{2}}−\mathrm{3}{x}\:\Rightarrow{x}=\frac{\pi}{\mathrm{36}} \\ $$