Find the binomial expansion of (a +b) ^6. For coefficient of each term use COMBIN function.?

Answer 1

The expansion is
a^6 + 6a^5b + 15a^4b^2 + 20 a^3b^3 + 15a^2b^4 + 6ab^5+ b^6
I'll use COMBIN(a,b) and write it as C(a,b).
C(6,0) =1
C(6,1) = 6
C(6,2) = 15
C(6,3) = 20
C(6,4) = 15
C(6,5) = 6
C(6,6) = 1
You can get these directly from Pascal's triangle.
Look it up in Wikipedia.

Answer 2

6c0(a^6xb^0)+5c1(a^5xb)+6c2(a^4xb^2)+6c3(a^3xb^3)+6c4(a^2xb^4)+6c5(axb^5)+6c6(a^0xb^6)