Nyatakan penjumlahan berikut dalam notasi sigma ! 1/2+2/3+3/4+........+75/76

jawab

1/2 + 2/3 + 3/4+ ....+75/76

= 1/(1+1) + (2)/(2+1) + (3)/(3+1)  + ....+(75/(75+1)
= n/(n+1)

75
∑  k/(k+1)
k = 1