log9(9a+b)=log3√ (ab),求4a+b 的最小值,
log9(9a+b)=log3√ (ab),求4a+b 的最小值,
数学人气:836 ℃时间:2020-05-21 17:00:15
优质解答
log9(9a+b)=log3√ (ab),0.5log3(9a+b)=log3√ (ab),log3√ (9a+b)=log3√ (ab),9a+b=ab,b=9a/(a-1),4a+b=4a+9a/(a-1)= (4a+5a)/(a-1)=[4(a-2a+1)+13(a-1)+9]/(a-1)=4(a-1)+13+9/(a-1)>=13+2√ [4(a-1)*9/(a-1)]=...
我来回答
类似推荐
猜你喜欢