meili 发表于 2022-10-27 15:03:47

已知函数f(x)=㏒4(4呢x次方加一)+kx(k∈R)(1)若k=0求不等式f(x)>amp;#189;的解集.(2)若f(x)为偶函数,求k的值.

<p>问题:已知函数f(x)=㏒4(4呢x次方加一)+kx(k∈R)(1)若k=0求不等式f(x)>amp;#189;的解集.(2)若f(x)为偶函数,求k的值.
<p>答案:↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">李会容的回答:<div class="content-b">网友采纳  (1)k=0时,f(x)=log(4,4^x+1)>1/2  4^x+1>2,所以4^x>1,解得x>0,解集为(0,+∞)  (2)f(-x)=f(x)  log(4,4^(-x)+1)-kx=log(4,4^x+1)+kx  2kx=log(4,/(4^x+1)]  2kx=log(4,4^(-x))=-x  k=-1/2.
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