For example,
consider one of the following relationships between x and y:
x – y – π = 0
x + sin xy – y = 0
In the first case, we can solve for y and rewrite the relationship as y = x – π In
the second case, it does not seem that there is an easy way to solve for y Nevertheless,
there is no doubt about the dependence of y on x in either of the cases When a
relationship between x and y is expressed in a way that it is easy to solve for y and
write y = f(x), we say that y is given as an explicit function of x