Which of the following function represents a simple harmonic oscillation

$x=\sin \left(\omega t\right)-\cos \left(\omega t\right)=\sqrt{2}\sin \left(\omega t-\frac{\pi }{4}\right)$ is a SHM with angular frequency $\omega$.

$x={\sin }^2\left(\omega t\right)=\frac{1}{2}-\frac{1}{2}\cos \left(2\omega t\right)$ is a SHM about equilibrium position $x=\frac{1}{2}$ with angular frequency $2\omega$.

The last two equations do not represent SHM because multiple frequencies are present in each case.