Consider the continuous-time sinusoid x(t) sin(2nt/T). A symbolic expression can be created to represent x(t) within MATLAB as x=str2sym('sin(2*pi*t/T'). The variables of x are the single character strings 't' and 'T'. The function fplot can be used to plot a symbolic expression which has only one variable, so you must set the fundamental period of x(t) to a particular value. For example, if T = 3, you can use subs as follows: x5=subs(X, 'T',3). Thus, x5 is a symbolic expression for sin(2nt/3).

Plot three periods of sin(2πt/3) beginning at t= 0 using fplot.