(1): log(5)2=b, 1/log(2)5=b, log(2)5=1/b, log(2)5+1=1/b+1, log(2)5+log(2)2=(b+1)/b, log(2)10=(b+1)/b, lg2=1/log(2)10=b/(b+1). (2): log(4)27=a, log(2^2)3^3=a, (3/2)*log(2)3=a, log(2)3=2a/3, lg3/lg2=2a/3,[log(a)b=log(c)b/log(c)a] lg3=lg2*2a/3=2ab/3(b+1)
答：an=log(n+1)(n+2)=ln(n+2)/ln(n+1) 所以: 数列的前30项的乘积={ln(3)/ln(2)}*{ln(4)/ln(3)}*...*...详情>>
答：One Sunday, Mark decided to go sailing in his boat with his friend Dan, but Dan ...详情>>
