log(2)5=a,log(2)7=b用ab表示log(35)28
问题描述:
log(2)5=a,log(2)7=b用ab表示log(35)28
答
log(2)5=a,log(2)7=b
a+b=log(2)35
log(35)28=log(2)28/log(2)35
=[log(2)4+log(2)7]/log(2)35
=(2+b)/(a+b)
答
log(35)28
=log2 28/log2 35
=(log2 4+log2 7)/(log2 5+log2 7)
=(2+b)/(a+b)