Mathematica Troubleshooting Guide

Common Errors

• Check Capitalization.
  All built-in Mathematica commands start with a capital letter, including ``E'' (the number 2.7182...). Many also have internal capitalization, like ``FindRoot''.

• Did you use the correct Parentheses/Brackets/Braces?
  
  • Parentheses for arithmetic grouping: (a+b)*c
  • Curly brackets for lists: {a,b,c}
  • Square brackets for arguments of functions: f[x_,y_]

• Did you use an underscore for dummy variables when defining a function?
  For example, f[x_,y_]=x*y^2

• Did you Clear functions and variables before defining them?
  If you have been using primes for differentiation, you should also clear the derivative when you redefine the function. For example, if you have been using a function f[x] and its derivative f'[x], running ``Clear[f,Derivative]'' will guarantee that f'[x] will correspond to the current definition of f[x].

• Check for spaces between variables.
  ``ab'' is interpreted as a word (a single variable name) and is NOT the multiplication of a and b. Add a space for multiplication (a b) or, better yet, use an asterisk for multiplication to avoid the confusion.

• Did you re-run the input cells, if you re-opened a notebook?
  When you re-open a notebook, the typing is still there, but Mathematica will have forgotten all the definitions (in fact, ALL of the output ...) until you run those cells again.

• Did you run the initialization cells?
  You should always run the initialization cells. They contain hidden commands and definitions (functions, constants, etc.) that the instructor has entered and which you will need to run the notebook.

• Stopping a Runaway Process Try to abort the process using the ``Abort Evaluation'' command in the pull-down menu under ``Kernel'' at the top of the Mathematica notebook or by holding down both the diamond(or Alt) key and the period simultaneously.