Math 99 Email hints:

Here are some ideas that should help:

• Use "^" to represent superscripts, as in "x^2" for "x squared", and "x^(1/2)" for "the square root of x". Use parentheses to avoid confusion about what belongs in the power. E.g., "x^(2x)+1" rather than "x^2x + 1" since this could be read incorrectly as either "(x^2)x + 1" or "x^(2x+1)".

• Use "_" to represent subscripts, as in "x_i" for "x sub i". Use parentheses as above to make more complicated subscripts clear.

• Use spaces around low-precedence operators like addition, subtraction and equals, but not around multiplication and division, as in "2x^2 + 3 = -1" rather than "2x^2+3=-1"

• Use parentheses to make the numerator and denominator clear when you write fractions using "/", as in "(x+1)/(2x-3)", not "x+1/2x-3" since this could be read as "x + (1/2)x - 3" or any of a number of other ways.

• For long equations, set them off from the rest of the mail by blank lines and indentation. For example:

     I can't figure out how to factor the equation
  
          x^3 - 2x^2 + 1 = 0
     
     Can you give me any advice?    
  

• Use spaces, not tabs, of you are forming a multi-line equation (like a large fraction or a series of equalities). E.g.

                  1
       f(x) =  -------
                1 - x
                
                 -1
   so f'(x) =  -------
               (1-x)^2
  

• In general, use spaces and parentheses liberally to make your meaning as clear as possible.

• For symbols that don't appear on the keyboard, like the subset symbols, or the "is an element of" symbol, simply write out the words for the symbol. E.g., "If x is an element of A then x is an element of B", or more simply "If x is in A then x is in B".

• Use "/=" or "!=" for "not equal". Similarly, "/<", "/>", etc.