Calculating infinite series of roots

[Helge Gabert]

There is no symbol for repeated exponentiation on the calc, as opposed to the repeated summation and product operator, so I'm not sure if you can show that symbolically with the limit function.

But, of course, you can always write a program and show that numerically, you get very close to 2. For example, with a REPEAT ... UNTIL loop, using approx(sqrt(2)), and setting your tolerance at 1E-12, you get to 2 after 71 iterations, after which the result doesn't change any more.