Question

How do you find the coefficient of `x^4` in the expansion of `(x+2)^8`?

Answer 1

Co-efficient of `x^4` is `1120`

Explanation:

`(x+2)^8= x^8+nc_1x^7*2^1+nc_2x^6*2^2+nc_3x^5*2^3+ nc_4x^4*2^4+..............+2^8`

Co-efficient of `x^4` is `nc_4*2^4 = (8!)/(4!*4!)*16=70*16=1120`[Ans]