elementary differential geometry o solution
vature of the helix \( \mathbf{r}(t) = (\cos t, \sin t, t) \). Solution: \( \mathbf{r}'(t) = (-\sin t, \cos t, 1) \) \( \mathbf{r}''(t) = (-\cos t, -\sin t, 0) \) Cross product: \[ \mathbf{r}'(t) \times \mathbf{r}''(t) = (1 \cdot 0 - \cos t \cdot (-\sin t), -\sin t \c