# How can I get Mathematica to simplify my square root expression? [duplicate]

$$\sqrt{r^2 e^{4 \gamma (r)-4 \psi (r)}}$$

If I set

var = r^2*E^(4 \[Gamma][r] - 4 \[Psi][r])

Simplify[Sqrt[var], var > 0]


I just get

$$\left| r\right| \sqrt{e^{4 \gamma (r)-4 \psi (r)}}$$

How to tell Mathematica to perform the full square root calculation?

$$r e^{2 \gamma (r)-2 \psi (r)}$$

• ya r has been taken...simple mathematical rule Simplify[Sqrt[(r^2)*E^(4 \[Gamma][r] - 4 \[Psi][r])]]//PowerExpand – Rorschach Jul 5 '13 at 19:24
• Thank you! Why does it work? – Giovanni F. Jul 5 '13 at 19:32
• Your concern is code snippet or 'r' ? – Rorschach Jul 5 '13 at 19:33
• My concern is to get rid of the square root. – Giovanni F. Jul 5 '13 at 19:35
• Use e.g. Simplify[ Sqrt[var], r \[Element] Reals && (4 \[Gamma][r] - 4 \[Psi][r]) \[Element] Reals] – Artes Jul 5 '13 at 19:51