If you don't mind a web-based solution, wolframalpha.com will do that for you:
http://www.wolframalpha.com/input/?i=2^1000
outputs:
10715086071862673209484250490600018105614048117055336074437503883703510511249361224931983788156958581275946729175531468251871452856923140435984577574698574803934567774824230985421074605062371141877954182153046474983581941267398767559165543946077062914571196477686542167660429831652624386837205668069376
You used the if operator incorrectly. The format is
if( condition, what to do if True, what to do if False)
But you put another condition in the place of "what to do if false".
Here's an example: I want a function which is equal to $3x$ between $x=1$ and $x=4$, is equal to $x+8$ between $x=4$ and $x=5$, and is undefined otherwise. The code could be
if(x>5, ln(0), if(x>4, x+8, if(x>1, 3*x, ln(0) ) ) )
Here I'm using $\ln(0)$ with the hope that it will simply produce no output for the corresponding range, rather than halt the entire computation. Don't have the app (or iPad for that matter), so can't tell for sure.
Best Answer
Updated, December 2018: I made the following website with the aim of producing a Desmos-like experience in 3D for my multivariable calculus students.
math3d.org
You can create and animate points, vectors, curves, surfaces (explicit & implicit), and vector fields. After creating a demonstration, you can save it and share.
Here are three scenes that I particularly like:
This project is on Github. If you find bugs or have ideas for improvements, please open an issue!