What is the expansion of (x + 1)^4(x+1)4?

1 Answer
Sep 24, 2016

(x+1)^4=x^4+4x^3+6x^2+4x+1(x+1)4=x4+4x3+6x2+4x+1

Explanation:

According to Binomial Theorem expansion of (x+a)^n(x+a)n is

x^n+nx^(n-1)a+(n(n-1))/(2!)x^(n-2)a^2+(n(n-1)(n-3))/(3!)x^(n-3)a^3+(n(n-1)(n-3)(n-4))/(4!)x^(n-4)a^4+.....+a^n

Hence (x+1)^4=x^4+4x^3xx1+(4xx3)/(2xx1)x^2xx1^2+(4xx3xx2)/(3xx2xx1)x xx1^3+(4xx3xx2xx1)/(4xx3xx2xx1)1^4

= x^4+4x^3+6x^2+4x+1