Every term of
is of the form
, where k = 0,1,2,3,4,5,6
Write
as
Write
as
Write
as
Rearrange the factors:
Add the exponents of x
For the term to be independent of x, the power of x
must be 0, since x0 = 1 which contains no x.
So we set the exponent of x equal to 0:
So we substitute k=2
Edwin