PowerExpand expands all powers of products and powers. PowerExpand[var1, var2, …] expands only with respect to the variables var1, var2, …Expand a power of a product:
def t = '(a*b*c)**d'.t println PowerExpand >> t
> a**d*b**d*c**d
Expand with respect to a:
def t = '(a*b*c)**d'.t println PowerExpand['a'] >> t
> a**d*(b*c)**d
Expand a square root:
def t = '(a*b)**(1/2)'.t println PowerExpand >> t
> a**(1/2) * b**(1/2)