Functions,
3 limits,
derivatives
3.1 Functional notation As we progress in a study of a science, it is
necessary to become familiar with terminology and notation used for con-
veying information. One of the most important
mathematical words is the word function. We
may look at Figure 3.11, in which x, y, and z are
the lengths of the sides of a triangle and 8 is the
angle at the vertex V opposite the side of length z, Figure 3.11
and say that z is a function of x, y, and 0 which we
shall denote by f(x,y,B). By this we mean that when x, y, and 0 are
given numbers for which x > 0, y > 0, and 0 < B < r, the number z
is completely determined and has a value which we denote by the symbol
in the right member of the formula
(3.12) z = f(x,y,B).
III