      color      = red,
         key        = &quot;Linear interpolator&quot;,
         explicit(f(x),x,-5,20),
         point_size = 3,
         color      = blue,
         key        = &quot;Sample points&quot;,
         points(args(p)))$
(%i9)  /* Change variable name */
       linearinterpol(p, varname='s);
       13   3 s
(%o9) (-- - ---) charfun2(s, minf, 3)
       2     2
 + (s - 5) charfun2(s, 7, inf) + (37 - 5 s) charfun2(s, 6, 7)
    5 s
 + (--- - 3) charfun2(s, 3, 6)
     3
</pre>
</dd></dl>



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