How do I calculate complex math functions?

How Scientific Is Calculated

Enter a value and select an operation. For trigonometric functions, choose whether to use degrees or radians. The calculator applies the mathematical function and returns the result.

Applies selected operation to value: sin/cos/tan (radians or converted from degrees), sqrt (if value>=0), log=log10 (if value>0), ln=natural log (if value>0), square=value^2, cube=value^3, default=identity
Also always returns: reciprocal = 1/value, absolute = |value|, factorial = n! of floor(|value|)
Where:
value = input number (default 45); operation = selected function; angleUnit = 'degrees' or radians, converts degrees to radians for trig
Assumptions:
sqrt/log/ln return 0 for invalid domain instead of NaN/error
factorial only defined for non-negative integers; returns Infinity for n>170, NaN(->0) otherwise
result/reciprocal rounded to 10 decimal places