# size and location of cube root symbol [duplicate]

Possible Duplicate:
Nice-looking p-th roots

On math.stackexchange I wanted the cube root of a fraction in display mode, and used $$\sqrt[3]{\frac ab}$$ to get it. The 3 comes out very small and low in the root sign. I also thought of $$^3\sqrt{\frac ab}$$ but the 3 comes out too far to the left.

$\sqrt[3]{\frac{a}{b}}\qquad \sqrt[\leftroot{-1}\uproot{2}\scriptstyle 3]{\frac{a}{b}}\qquad \Bigl(\frac{a}{b}\Bigr)^{1/3}$