Asked by Rob
Expanding the trinomial, (x+y+z)^n, gives terms X^rY^sZ^t where r+s+t=n and with a coeficient of n! over r!s!t!.
a. use this pattern to expand (x+y+z)^3.
b. find the sum of the coeficients in the expression of (x+y+z)^n.
(LET x=y=z=1.)
a. use this pattern to expand (x+y+z)^3.
b. find the sum of the coeficients in the expression of (x+y+z)^n.
(LET x=y=z=1.)