X ′ a = ∂ x ′ a ∂ x b X b {\displaystyle X{{'}^{a}}={\frac {\partial x{{'}^{a}}}{\partial {{x}^{b}}}}{{X}^{b}}}
MERKE koWariant-->bleoW X ′ a = ∂ x a ∂ x ′ b X b {\displaystyle X{{'}_{a}}={\frac {\partial {{x}^{a}}}{\partial x{{'}^{b}}}}{{X}_{b}}}
