用lg2,lg3表示下列对数:(1)lg根号6,(2)lg2.4,(3)lg20,(4)lg30,(5)lg200,
问题描述:
用lg2,lg3表示下列对数:(1)lg根号6,(2)lg2.4,(3)lg20,(4)lg30,(5)lg200,
(6)lg3/2
答
(1)lg2+lg3
(2)lg12/5=lg12+lg5=lg2*2*3+lg10/2=2lg2+lg3+1-lg2=lg2+lg3+1
(3lg2*2*5=2lg2+lg5=lg2+1
(4)lg3*2*5=lg3+lg10=lg3+1
lg2*100=lg2+2