You must specify a variable, but so what? It is 'one' line of programming and one keystroke during integration. And it's no problem at all once you get the hang of it. It is not much different from the 15C and can be mastered very quickly.
Here is a simple example: Integrate 5x^2-3, from x=0 to x=2. (The answer is 7.33)
On the 15C, you would write a simple program:
001 LBL 1
002 x^2
003 5
004 *
005 3
006 -
007 RTN
Then you enter your limits of integration, 0 ENTER 2, and Integrate whatever program label contains the equation.
On the 35s, the procedure is as follows:
Write a program with the same equation as above, but call it LBL I as an example. Here goes...
I001 LBL I
I002 INPUT X
I003 x^2
I004 5
I005 *
I006 3
I007 -
I008 RTN
Then press LS FN= 'I' to specify the program label to be executed/integrated, enter the limits of integration as per the 15C, and Integrate 'X'. That's all there is to it.
Jeff
Edited: 15 July 2009, 6:19 p.m.