Binomial Expansion

Cards (2)

  • Binomial coefficient for n choose r:
    (nr)=\binom{n}{r}= n!r!(nr)!\frac{n!}{r!\left(n-r\right)!}
  • Binomial expansion formula
    (1+x)n=\left(1+x\right)^n= 1+1+nx+nx+n(n1)2!x2+\frac{n\left(n-1\right)}{2!}x^2+n(n1)(n2)3!x3+\frac{n\left(n-1\right)\left(n-2\right)}{3!}x^3+...... for x<1\left|x\right|<1