(log2^3 +log3^5) x ( log3^5 +log9^5 ) x lg 2 ,
问题描述:
(log2^3 +log3^5) x ( log3^5 +log9^5 ) x lg 2 ,
本人对数特别差,最好带解说,
(log2^3 +log5^3) x ( log3^5 +log9^5 ) x lg 2
答
对数连底都没有!有,比如第一个对数,就是以2为底,3的对数,只是不知道怎么打,所以这样写了,求解!!刚刚题目写错了,我修改了,求高手解决啊!!!帮帮忙啦(log2^3 +log5^3) x ( log3^5 +log9^5 ) x lg 2
=(log2^3 +log5^3) x ( log3^5 +1/2log3^5 ) x lg 2
=3/2(log2^3 +log5^3) xlog3^5x lg 2
=3/2log2^3xlog3^5x lg 2 +3/2log5^3 xlog3^5x lg 2
=3/2log2^5x lg 2 + 3/2lg 2
=3/2lg 5 + 3/2lg 2
=3/2 (lg5 +lg 2)
=3/2