Lean-Workbook Plus 44804: Trigonometric identity

The map $t\mapsto(\cos t,\sin t)$ from $\mathbb R$ to $\mathbb R^2$ is continuous.

Source: Lean-Workbook row lean_workbook_plus_44804 (Apache-2.0). The unchanged proposition comes from the original record; its missing mathematical imports and namespaces are restored here.