A class of non-convex functions

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What are some examples of not necessarily convex functions mapping $\mathbb{R}^n \rightarrow \mathbb{R}$ which are smooth, have gradients of bounded norm and have a global/local minima? I would be delighted see some non-trivial non-oscillating parametric families of such functions!

The easiest examples of this type that I can think of are $\sin$ and $\cos$.