Students in calculus learn the product rule of differentiation as (f*g)'= f'*g+f*g', but a common mistake is taking the product rule as (f*g)'= f'*g'.
Usually that answer is wrong, but there are pairs of functions f and g where the wrong product rule generates the right answer.
If f,g is one of those special pairs and f=xn (n≠0), then what is function g?
