Numerical answers may be given in standard or scientific notation:
• -1.57
• 3.853e-23
• Do not put commas in numbers. Use 23456 not 23,456.

• You may refer to the constants and fixed variables in any problem by name:
• Pi and pi are always 3.14159265...
• 3*e0

• Operations
• Arithmetic operations are * / + -
• Implicit multiplication is not recognized. Use 3*a, not 3a. Use g*(H+h), not g(H+h).
• Powers use ^, as x^2 is x2
• Order of operation: ^ precedes * or / which in turn precedes + or -. x^2/3 and x^(2/3) are different as are 2/3*5 and 2/(3*5).
• Use parentheses liberally to avoid ambiguity and errors.

• Functions
• Square root: either sqrt(x) or x^(1/2) are OK.
• ex is exp(x)
• ln(x) is log(x) or ln(x)
• log10(x) is log10(x)

• Trigonometric Functions
• Note that angles are always given in radians!

• sin(x) is sin(x), etc.
• PHP, the language we use for the website, does not recognize csc(x), sec(x) or cot (x). Use 1/sin(x), 1/cos(x), and 1/tan(x) for these.
• sin-1(x) is asin(x), etc.
• tan-1(y/x) can also be written as atan2(y,x), etc. This form is superior when there can be a question of quadrants.