They are all the same, but if you take a number's reciprocal and square it by the number, and the number is a power of 2, you get the square root of 2, NOT 1. This is because when you simplify the other equations, you get the square root of 2, every single time under these conditions. Remember, fractions as exponents are square roots to the power of the reciprocal of the fraction. Therefore they are all the same. Around 1.41421356237 ish, but the decimal never ends.