My problem:
Find the coefficient of the term containing in the expansion of
I have to find the general term and compare it with the required term.
I need to apply the rth formula in the expansion of to find the general term.
I figured out that n = 8 and a = 1.
What I don't understand is how the exponent for b which equals x =
TIA...
See image:
r has to 7. why would you say 4? remember, is a term with a 1/2 power, we have to account for that. if r = 7, then r - 1 = 6 and 6*(1/2) = 3, which is the power we are after
i've always used ........using this formula (of course we forget about the sum, we just care about one term), we plug in r = 6 and we're home