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### SQR

 Keyword Abbreviation Token (hex) Version(s) Classification SQR S{Shift+Q} BA 1.0+ Function

SQR value )

 Parameters Type Legal Value(s) Note(s) value Numeric any non-negative

 Returns Type Value(s) Note(s) base Floating-point any non-negative

 Purpose
Calculate the square root of non-negative number.

 Remarks
The SQR function calculates a result which, if multiplied by itself, yields the supplied value.  In math symbols, it solves for base in the equation
value = base2 = base * base

Because no real number (base), when multiplied by itself can give a negative value, an ILLEGAL QUANTITY ERROR will be gnerated if you supply a negative value.  If the value is omitted or not a valid expression, SYNTAX ERROR is generated.  If the value is not numeric, a TYPE MISMATCH ERROR occurs.

It is especially useful in triginometry, or any time you want to calculate the "Euclidian Distance".  A common example is conversion from "rectangular" to "polar" coordinates, where SQR would give you the "polar length".  Similarly, complex numbers may be emulated in BASIC and SQR is then useful to calculate the "magnitude" of a complex number.

BASIC does not limit you to square (2nd) roots , you can calculate cube (3rd) roots too (for example) by using the power operator (^).  BASIC actually calculates the SQR as value ^ 0.5 which is the same as value ^ (1/2).  Anyway, to calculate a cube (3rd) root, use value ^ (1/3).

Examples:
 ```PRINT SQR(25) 5 READY. PRINT SQR(10) 3.16227766 READY. DX = 5: DY = 8 : REM real,imaginary of complex OR x,y of rectangular coordinate READY. PRINT SQR(DX*DX + DY*DY) 9.43398114 magnitude of complex number OR length of polar coordinate READY. ```

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