Leg punt geen viii uit?

Leg punt geen viii uit?
Anonim

Antwoord:

Zie de uitleg hieronder

Uitleg:

# "^ NC_r = ((n), (r)) = (n!) / (R? (N-r)!) #

De eerste term is

# S_1 = "^ rC_r = (r!) / (R! (R-r)!) = 1 #

# S_1 = ((1 + 1)!) / ((1 + 1)! (1-1)!) = 1 #

De eerste plus de tweede term is

# S_1 + S_2 = "" ^ rC_r + "^ (r + 1) C_r = 1 + ((r + 1)!) / (R! (R + 1-r)!) = R + 1 + 1 = r + 2 #

# S_2 = ((r + 1 + 1)!) / ((R + 1)! (R + 1-r)!) = ((R + 2)!) / ((R + 1)? (1?)) = r + 2 #

Het resultaat is dus geverifieerd.

# "^ (n + 1) C_ (r + 1) = ((n + 1)!) / ((r + 1)! (n + 1-r-1)!) = ((n + 1)!) / ((r + 1)! (nr)!) #