Calculate a square and a square root!

C and C++, 68 65 bytes

#include<math.h>
float f(float n){auto p=.5;return pow(n,2-p*3);}

Original answer:

#include<math.h>
float f(float n){return pow(n,sizeof('-')-1?2:.5);}

For both versions, C produces n^2 and C++ produces sqrt(n).

lambda n:n**(1/2or 2)

Python 2.x produces n^2, Python 3.x produces sqrt(n).

_{2 bytes saved thanks to @Dennis!}

Square root in Jolf, square in MATL.

Try it online! (MATL)

Try the Jolf code. Only works on Firefox.

These are both 1 byte, as MATL and Jolf both use ASCII/extended ASCII codepages, so all commands are 1 byte.