# Easy way to derive rotation matrix

It is very easy to derive rotation matrix. This method is applied to general cases. Derivation Step1. Calculate rotation of unit vectors Step2. Arrange two vectors Background: Why can we derive? Derivation Step1. Calculate rotation of unit…

# Useful knowledge for calculation

Prefix Pressure Others Density of water: Water pressure: Prefix Name Symbol $10^n$ kilo k $10^3$ hecto h $10^2$ deca da $10^1$ $10^0$ deci d $10^{-1}$ centi c $10^{-2}$ Pressure \begin{align} 1 \mathrm{\,Pa}&=1 \mathrm{\,N/m^2}\\ \text{Atm…

# Contraction of completely anti-symmetric tensor

Contraction formula of the completely antisymmetric tensor (or Levi-Civita symbol) is indispensable for vector calculus.If you think it is hard to remember the formula, it is wrong. Actually, the derivation is very easy.At the end of this …