**The binomial expansion**
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It is customary to call the expression (1 + x)*n* the Newton's binomial, even though it was used well before Newton was born, in particular by Persian mathematicians as early as the 10th century, as was the associated "Pascal's triangle". The binomial formula concerns the expansion of (1 + x)*n* as a sum of multiples of the polynomials 1, x, x2, x3, etc.
For n = 2 and n = 3, we find the well-known identities (1 + x)2 = 1 + 2x + x2 and (1 + x)3 = 1 + 3x + 3x2 + x3.
