設各項均為正數的數列{an}和{bn}滿足5^an,5^bn,5^an+1成等比數列,lgbn,lgan+1,lgbn+1成等差數列,且a1=1,b1=2,a2=3,求通項an,bn猜想:an=n(n+1)/2 bn=(n+1)*(n+1)/2假如用數學歸納法做的話當n=k+1時怎麼寫啊?

設各項均為正數的數列{an}和{bn}滿足5^an,5^bn,5^an+1成等比數列,lgbn,lgan+1,lgbn+1成等差數列,且a1=1,b1=2,a2=3,求通項an,bn猜想:an=n(n+1)/2 bn=(n+1)*(n+1)/2假如用數學歸納法做的話當n=k+1時怎麼寫啊?

將a(k+1)=(k+1)(k+2)/2 b(k+1)=(k+2)^2/2代入已知的等比數列的等差數列看是否成立就行了