> i1 := t^2;

> j1 := 2*t;

> k1 := ln(t);

> with(plots);

> spacecurve([i1,j1,k1],t=0..5, axes=normal, color=red, numpoints=100, labels=[x,y,z]);

> i2 := diff(i1,t);

> j2 := diff(j1, t);

> k2 := diff(k1, t);

> D1 := evalf(simplify((i2^2 + j2^2 + k2^2)^(1/2)));