# Function xgcd Calculate the extended greatest common divisor for two values. See https://en.wikipedia.org/wiki/Extended_Euclidean_algorithm. ## Syntax ```js math.xgcd(a, b) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `a` | number | BigNumber | An integer number `b` | number | BigNumber | An integer number ### Returns Type | Description ---- | ----------- Array | Returns an array containing 3 integers `[div, m, n]` where `div = gcd(a, b)` and `a*m + b*n = div` ### Throws Type | Description ---- | ----------- ## Examples ```js math.xgcd(8, 12) // returns [4, -1, 1] math.gcd(8, 12) // returns 4 math.xgcd(36163, 21199) // returns [1247, -7, 12] ``` ## See also [gcd](gcd.md), [lcm](lcm.md)