# Simplifying an exponential expression [duplicate]

I have an expression: (1/a^13)^(1/13)

I want Mathematica to simplify it to '1/a'. How do I do it? 'Simplify' and 'FullSimplify' don't work.

Please be sure what you are doing! Mathematica always treats variables to be complex by default. Are the power laws correct in this general assumption? Here you can go with

PowerExpand[(1/a^13)^(1/13)]


but don't forget the warning in its documentation:

The transformations made by PowerExpand are correct in general only if c is an integer or a and b are positive real numbers.

• How do you make the text appear in gray? – Sashwat Tanay Dec 3 '14 at 17:37
• You indent this line by 4 spaces. Please see here for a detailed tutorial. – halirutan Dec 3 '14 at 17:38

Ah, I got to know the answer at another page on this site on simplifying an expression. The point is to make 'Assumptions' in Mathematica

So, the following works:

Simplify[(1/a^13)^(1/13), Assumptions -> a > 0]


Or one can declare Assumptions separately.