numerical analysis: (mathematics) the branch of mathematics that studies algorithms for approximating solutions to problems in the infinitesimal calculus
pure mathematics: the branches of mathematics that study and develop the principles of mathematics for their own sake rather than for their immediate usefulness
relativistic mass: (physics) the mass of a body in motion relative to the observer: it is equal to the rest mass multiplied by a factor that is greater than 1 and that increases as the magnitude of the velocity increases