Comparing and .

Since for positive (proof: and at ), if we set ,

Generally, for real , we have with the equality holds only at . Therefore,

and the equality holds only at or .

Alternative way to prove is to compare and . Consider

Comparing and .

Since for positive (proof: and at ), if we set ,

Generally, for real , we have with the equality holds only at . Therefore,

and the equality holds only at or .

Alternative way to prove is to compare and . Consider