In order to enter the exponential function, , in Maple, you must
use the `exp` command. The syntax of this command is similar to
that of `sin` and `cos`. For example, here we enter the
function and then evaluate at *x* = 2.

> f:=exp(x);

> evalf(subs(x=2,f));

The natural log function, `ln`, is also used in this manner.

> g:=ln(x);

> evalf(subs(x=2,g));

Plotting the two functions and on the
same coordinate system gives an idea of the symmetry around the line
*y*=*x*. Make sure that you can identify which curve is and which
curve is .

> plot(f,g,x,x=-5..5,y=-5..5);

Looking at the graph of the two functions, you can get a pretty good
idea of what happens to *f*(*x*) as *x* approaches negative infinity;
however,in order to be sure, you must take a limit.

> limit(f,x=-infinity);

Tue Sep 24 13:59:38 EDT 1996