Question

How do you use the binomial series to expand `(1 + x)^4`?

Answer 1

Use the pascal's triangle to find the answer easily:

`rarr(a+b)^4=1a^4+4a^3b+6a^2b^2+4ab^3+1b^4`

`rarr(1+x)^4=1(1)^4+4(1^3)x+6(1^2)x^2+4(1)x^3+1(x^4)=1^4+4x+6x^2+4x^3+1(x^4)=1+4x+6x^2+4x^3+x^4`