I have been thinking on this topic for a while. As I have seen on various sites: 1) a^(b/c) means "c"th root of "a^b". 2) Also an even root of a negative number does not exist in real numbers. Then I want to investigate this formula: a=(-4)^(1/2) Mustn't it be equal to b=(-4)^(2/4) However if we calculate the power first; a=square root of [(-4)^1]= Not a real number b=4th root of[(-4)^2]= 2 What do I miss? I have some confussion about decimal exponents but I hope the answer of this question will solve it.