【设a=1/log4(4为底)3+1/log7(7为底)3,则a的取值范围】
<p>问题：【设a=1/log4(4为底)3+1/log7(7为底)3,则a的取值范围】<p>答案：↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">秦绪柏的回答：<div class="content-b">网友采纳 a=1/log43+1/log73=log34+log37=log3(4*7)=log328>log327=log33^3=3;得a>3;注意对数公式的灵活运用:1/logab=1/(lgb/lga)=lga/lgb=logba
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