等比数列,设公比为q,首项a1
L,m,n项分别是aL,am,an
(aL)^(m+n)*(am)^(n-L)*(an)^(L-m)
=(a1q^(L-1))^(m+n)*(a1q^(m-1))^(n-L)*(a1q^(n-1))(L-m)
=a1^(m+n)*a1^(n-L)*a1^(L-m)*q^((L-1)(m+n)+(m-1)(n-L)+(n-1)(L-m)
=a1^0*q^0
=1
等比数列,设公比为q,首项a1
L,m,n项分别是aL,am,an
(aL)^(m+n)*(am)^(n-L)*(an)^(L-m)
=(a1q^(L-1))^(m+n)*(a1q^(m-1))^(n-L)*(a1q^(n-1))(L-m)
=a1^(m+n)*a1^(n-L)*a1^(L-m)*q^((L-1)(m+n)+(m-1)(n-L)+(n-1)(L-m)
=a1^0*q^0
=1