PlanetPhysics/Position Vector

In the space , the vector directed from the origin to a point \,\, is the position vector of this point.\, When the point is variable, represents a vector field and its length a scalar field.

The simple formulae

are valid, where is the unit vector having the direction of .

If\, Failed to parse (syntax error): {\displaystyle \vec} \, is a constant vector,\, \, a vector function and\, \, is a twice differentiable function, then the formulae

  • Failed to parse (syntax error): {\displaystyle \nabla(\vec\cdot\!\vec{r}) = \vec}

hold.

All Sources

edit

[1]

References

edit
  1. {\sc K. V\"ais\"al\"a:} Vektorianalyysi . \,Werner S\"oderstr\"om Osakeyhti\"o, Helsinki (1961).