Fixed an issue in docstring.
Fixed an issue in docstring.

yashsharan/sympy,kaushik94/sympy,chaffra/sympy,skidzo/sympy,skidzo/sympy,yashsharan/sympy,chaffra/sympy,chaffra/sympy,jaimahajan1997/sympy,madan96/sympy,yashsharan/sympy,kaushik94/sympy,jaimahajan1997/sympy,kaushik94/sympy,madan96/sympy,jaimahajan1997/sympy,madan96/sympy,skidzo/sympy