Question

√2+√2√2.......infinity =

Answer 1

Now, notice that the part I've highlighted in red is actually equal to x itself. So we can replace it with x, to get the much simpler equation:

x = sqrt(2 + x)
x^2 = 2 + x
x^2 - x - 2 = 0
(x - 2)(x + 1) = 0
x = 2 or -1

and since x cannot be negative, x = 2. You won't see anything like this on the GMAT though, so it's for interest only.