Thread: Different ways of Counting ....

(a) Let n be a nonnegative integer. Use the identity

^

to show that (1)

(b) Prove (1) again by counting, in two different ways, the number of ways
of choosing n people from a set of n girls and n boys.

Originally Posted by shmounal

(a) Let n be a nonnegative integer. Use the identity

^

to show that (1)


Compare the coefficient of in both expressions above.

Tonio


(b) Prove (1) again by counting, in two different ways, the number of ways
of choosing n people from a set of n girls and n boys.

.