
11.3.6 Convolution of functions
Problem:
Find the convolution of the functions \( f(x) \) and \( g(x) \), if the function \( f(x) \) takes the value, equal to zero, when \( x \notin\left[x_{1} ; x_{4}\right] \), and when \( x \in\left[x_{1} ; x_{4}\right] \) its graph consists of links of the broken-line \( A B C D \) :
\[
\begin{array}{l}
A\left(x_{1} ; a\right), \quad B\left(x_{2} ; a\right), \quad C\left(x_{3} ; b\right), \quad D\left(x_{4} ; 0\right) . \\
x_{1}=-1, \quad x_{2}=1, \quad x_{3}=4, \quad x_{4}=6, \quad a=-1, \quad b=2 .
\end{array}
\]
The function \( g(x) \) has the form
\[
g(x)=\left\{\begin{array}{ll}
0, & x<0 ; \\
1, & 0 \leq x<1 ; \\
0, & x \geq 0 .
\end{array}\right.
\]