 <p>If you want to use the symbolic toolbox, define functions of type symfun:</p> <pre><code>syms t x1(t)=A1*cos(w1*t); </code></pre> <p>now you can easily integrate:</p> <pre><code>Ix1=int(x1) xc(t)=cos(wc*t + Ix1(t)-Ix1(0)) </code></pre>