5) find an equation of the tangent plane at the given point.
\[
g(x, y)=e^{x / y},(6,1)
\]
equation:
3) TRUE OR FALSE:
a) for all rectors \( \vec{u}, \vec{v}, \vec{w} \in \mathbb{R}^{3} \),
\[
\vec{\omega} \times(\vec{v} \times \vec{u})=(\vec{\omega} \times \vec{v}) \times \vec{u}
\]
\( T \) or \( F \) ?
b) Let \( F: \mathbb{R}^{3} \rightarrow \mathbb{R}^{3} \) be a vector field of class \( C^{2} \). Then \( \operatorname{div}( \) curl \( F)= \)
\[
\nabla \cdot(\nabla \times F)=0
\]
T or \( F \) ?
c) If \( f \) is a \( c^{2} \) scalar function, then \( \nabla \times(\nabla f)=0 \).
\( T \) or \( F \) ?
