Question Number 205217 by hardmath last updated on 13/Mar/24
$$\mathrm{4}\:\mathrm{sin}\:\frac{\mathrm{x}}{\mathrm{2}}\:\centerdot\:\mathrm{cos}\:\frac{\mathrm{x}}{\mathrm{2}}\:=\:\mathrm{1} \\ $$$$\Rightarrow\:\mathrm{x}\:=\:? \\ $$
Answered by A5T last updated on 13/Mar/24
$$\mathrm{2}{sinx}=\mathrm{2}{sin}\left(\frac{{x}}{\mathrm{2}}+\frac{{x}}{\mathrm{2}}\right)=\mathrm{4}{sin}\left(\frac{{x}}{\mathrm{2}}\right){cos}\left(\frac{{x}}{\mathrm{2}}\right)=\mathrm{1} \\ $$$$\Rightarrow{sinx}=\frac{\mathrm{1}}{\mathrm{2}}\Rightarrow{x}=\mathrm{30}°+\mathrm{360}{n};\mathrm{150}°+\mathrm{360}{n} \\ $$