Please take notice: all questions related to mathematics or to the site should be posted at one of the CTK Exchange forums - it's the top selection in the navigation column on the left.
Questions via email will be rejected.
Use my email address only if there is indeed something very private you want to communicate.
When you post a question at the CTK Exchange, please mind choosing a meaningful subject line. This will help others locate the question and the answer if need be. This will also save my time by reducing the need to answer the same question several times over. "I need help", "I am stuck" and the like do not make sense as subject lines.
Before posting a question, please search the forums - perhaps yours has been already answered.
Please pay attention: this is not the place to get homework help. I do not answer urgent requests, but may help you with a problem if you show some of your work.