기록

35. Gradient Operator (Vector Differential Operator) Scalar Function $ \phi (x_{1},x_{2},x_{3}) $ $ \phi' (x_{1}',x_{2}',x_{3}')=\phi (x_{1},x_{2},x_{3}) $: Coordinate Transformation $ \frac{\partial \phi '}{\partial x_{i}'}=\sum_{j}^{}\frac{\partial \phi }{\partial x_{j}}\frac{\partial x_{j}}{\partial x_{i}'} $: Chain Rule $ x_{j}=\sum_{k}^{}\lambda _{kj}x_{k}' $: Inverse Coordinate Transformat..

29. Rectangular Coordinate Position: $ \vec{r}=\vec{r}(t) $ Velocity: $ \vec{v}\equiv \frac{d\vec{r}}{dt}=\dot{\vec{r}} $ Acceleration: $ \vec{a}\equiv \frac{d\vec{v}}{dt}=\frac{d^{2}\vec{r}}{dt^{2}}=\ddot{\vec{r}} $ Rectangular Coordinates (Unit Vector가 시간에 대한 상수) Position: $ \vec{r}=x_{1}\hat{e_{1}}+x_{2}\hat{e_{2}}+x_{3}\hat{e_{3}}=\sum_{i}^{}x_{i}\hat{e_{i}} $ Velocity: $ \vec{v}=\dot{\vec{r..