i have a √a and the same as a(12);
then it is equal to a(1×(12));
according to the identities ((an)k=a(nk)=a(n×k)) it is the same as a(1(12));
in this case it is the same as a√1=a1;
a1=a;
SO: I have proven a false statement a=√a;
could you help me understand the problem?