It works if you change the limits from minf, inf to alpha, beta. Richard Hennessy wrote: > > (%i2) integrate((a-x)^3*h(r*x-q),x,minf,inf); > > (out2) 'integrate((a-x)^3*h(r*x-q),x,minf,inf) > (%i3) changevar(%,y-(r*x-q)=0,y,x); >