famous ones include the classification of finite simple groups, the poincare conjecture, fermat's last theorem
Chat with our AI personalities
The hardest question is too difficult to conjure.
There is no "hardest" problem. Something that you might find hard might appear easy to someone else and conversely. Also, some of the harder problems do not have solutions yet - if they had been solved then they could not have been so hard!
That is based on opinion.
To answer your math questions. You must state your question for it to be answered.
"Difference" means subtraction. for example the "difference" between 9 and 2 is 7.