ROOT

Member Of Menu: 
Solv
Argument Types: 
Real
Complex
Symbol
Expression
Result Type(s): 
Real
Invertible: 
No
Valid In Expression: 
No
Stack Diagram: 
Expression1 Symbol1 Real3 → Real4
Expression1 Symbol1 Complex3 → Real4
Expression1 Symbol1 List3 → Real4

This operation takes an expression, a symbol to solve for and a real, complex or list of guesses and produces a root for the symbol in the expression. For an expression without an equal sign, a root for a variable is a real value for that variable for which the expression evaluates to zero. If the expression contains an "=" operation, it is treated like a subtraction and that expression is then used to search for a root.

The guess should be a value which you believe to be near a root. Alternatively, the guess can be a complex value. In this case, the real value of that complex value is used as the guess and the imaginary component is ignored. Also, a list of one, two or three real or complex values can be used as the guess. This allows multiple guesses which can help the root finding algorithm to find the appropriate root. Ideally, the guesses will be on either side of the actual root.

It is possible for the root finding algorithm to fail. In some cases, it will produce a warning that a root could not be found. Or, it may end up searching for the root forever. If after a reasonable amount of time, the operation does not complete, use the "Attn" button to interrupt the search.