ABSTRACT

The system consisted of two equations in two unknowns. The unknowns need not all occur in each equation; this is allowed for by including 0 as a possible value for the as. Generally the as and ks are real numbers, though all that is said still applies if complex numbers are used. In practice the coefficients are only known approximately and are given as decimal fractions. In physics entities like displacements, velocities or forces may be represented by vectors; the word 'vector' literally means 'carrier'. Numerical quantities such as temperatures, lengths, speeds or weights are called 'scalars', because they can be read off on a scale. If vectors are to serve purpose of describing the system, mathematicians must know how to add them and multiply them by scalars.