been having trouble getting results in CAS system

[webmasterpdx]

Parisse,
Ah, I didn't realize, we already have an arcLen() function.
So, I can use arcLen(y(x),x,a,b)
Of course, you are right....it's not easy to calculate using this format....is the same math internally.

So, if I set z:=1, n:=3, a:=0, b:=1

y = (1-x^3)^(1/3)

dy/dx = -x^2/((1-x^3)^(1/3))^2

(1+(dy/dx)^2)^(1/2) = ((-x^2/((1-x^3)^(1/3))^2)^2+1)^(1/2)

So, now, we can calculate int((1+(dy/dx)^2)^(1/2),x,0,1) like this, and it'll give a value of 1.

However int(((-x^2/((1-x^3)^(1/3))^2)^2+1)^(1/2),x,0,1) hangs for a minute and gives an answer of an integral...i.e. doesn't get solved.

Why does it work with dy/dx but not with the expanded form????
Thanks
-Donald