Buy a Password for Graphs, Step-by-Step Integrals, Determinants, and Matrix Inverses

Over 1,000,000 step-by-step integral solutions delivered since 1999!

"I feel that it paid for itself in the first day." - Dave


  • To understand what you get with the integrals, check out the free step-by-step derivatives.
  • A password costs $25.
  • Passwords are good for one year.
  • A password is good for 900 solutions.
  • If you forget your password, email with the name on the credit card used to buy it.
  • This system works, so if you have any trouble, email!
  • One-on-one tutoring is currently not available.

How to Buy a Password

  1. Click the next link.
  2. You will be linked to to pay securely.
  3. You get a shared temporary password to use right away.
  4. Later, you will get a unique permanent password.
  5. Write it down in your math book!

click to buy a calc101 password!

If you are paying in US dollars, you can use paypal at kagi.

Using Your Password

  1. Go to the integrals page, the curve sketching page, or the matrix algebra page.
  2. Enter your password.
  3. Enter your function or your matrix and operation.
  4. Press the "Do it" button.
  5. You will see the step-by-step solution in a few seconds.
  6. Your account will be debited for one solution.
  7. Print or save the answer for future reference.
  8. You can then do another problem or come back again later.

If you have trouble entering functions, take a look at the sample inputs in the stored examples off the home page.

It is very simple to get your answers once you are used to the right input style.

Send email if you have any questions or problems with the system, even if you have not bought a password. will not sell, rent, or give away your email address to anyone unless ordered to by a court of law.