These answers are provided completely free, and they will always be free. We look at questions from textbooks we used in our own classes that we think might be challenging, and we solve them and post these answers online for other students to study and learn from. We do not in any way wish to infringe on copyrights of any of the amazing authors that wrote these wonderful textbooks that helped millions of students worldwide to successfully learn and become graduates at their schools.


We do not post answers to all the questions in a book, only a selected few that we think might be extra challenging to solve and we always state the name of the book, the author, and publisher. We would also like to state for considerations sake that most of the questions we answer, have already been asked on many forum websites, with answers being provided (e.g. Yahoo Answers, Stack Exchange, Physics Forum, etc).


We release these answers under fair use for educational purposes, in hopes of helping others and we hope you take this into consideration. If we have in any way infringed on a copyrighted material, and you wish for us to remove the said material, we respectfully ask that you contact usĀ at with the following:

  • A physical or electronic signature of a person authorized to act on the copyright owner’s behalf.
  • Identification of the owner’s copyrighted work that is claimed to be infringed.
  • Identification of:
    • the material that is claimed to be infringing, for material stored by the service provider; or
    • the reference or link to material or activity claimed to be infringing, if the service provider is referring or linking users to an online location containing infringing material or activity.
  • The complaining party’s contact information.
  • A statement that the complaining party has a good faith belief that the infringing material is not authorized by the copyright owner, the copyright owner’s agent or law.
  • A statement that the information in the notice is accurate and, under penalty of perjury, that the complaining party is authorized to act on behalf of the copyright owner.

Thank you for your time and patience as we handle your notice, with the utmost attention and speed.