1 + 1/2 + 1/3 + 1/4 + .... + 1/100 =

1/100+50/100+33/100+25/100+20/100+1/100=130/100

sn=n/2(2a+(n-1)b
1/100=n/2(2x1+(n-1) (-1/2)
1/100=n/2(2+(-1/2)n+1/2)
1/100=2n -n^2/4+n/4
_________________ x 4
4/100=8n-n^2+n

4/100=-n^2+9n 
__________________ x100
4= - 100n^2+900n
100n^2-900n+4=0 
___________________ :4
25n^2-225n+1=0
25n(n-9)=-1
n=-1 atau n=9

lain kali ditulis apa yg ditanyakan