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2^x＋1=√8
2^x=√8-1
x=log(base 2)(√8-1)
x=0.871

or

2^x＋1=√8
log(2^x)=log(√8-1)
xlog2=log(√8-1)
x=log(√8-1)/log2
x=0.871


2007-04-15 15:12:10 補充：
ok,那我知道那裡出問題la題目漏了括號,現在我加上括號再做一次2^(x＋1)=√8log[2^(x+1)]=0.5log8x+1=0.5(log8/log2)x=0.5(log8/log2)-1x=1.5-1x=0.5

2007-04-15 21:13:56 補充：
or2^(x＋1)=√8x+1=0.5log(base 2)8x+1=0.5*3x=0.5

除了上面那位的方法,亦可嘗試下列的方法

2^(x+1) = √8
2^(x+1) = 2^(3/2)　＜＝[√8 = 8^(1/2) = (2^(3*1/2) = 2^(3/2)]
∴ x+1 = 3/2
　　 x = 1/2 //