Problem 120. radius of a spherical planet

imaginary planet?

Negative surface area??

Cmon I'm sure a bit more challenging problems would'nt harm the a players brain...

I would have preferred something a bit more challenging, like asking for the volume, given the surface area, rather than just the radius. Then, the two-step solution (solve for r from area, and volume from r) could be consolidated into one line (by raising the area amount to the 1.5 power and scaling the constants appropriately).

I don't know why the lead solution is like this with the regular expression. And i estime the time with tic and toc. It is not the best. What is the size here? can anybody tell me, thx.