✔ 最佳答案
√(x+2)-2x+a>0a>2x-√(x+2)y=2x-√(x+2)dy/dx=2-[1/2√(x+2)]=0x=-31/16a>-33/8 logax>x²a>10^x²/xy=10^x²/xdy/dx=(2ln10)(10^x²)-(1/x²)(10^x²)=0x=1/√(2ln10)a>[√(2ln10)][10^(1/2ln10)]
2012-08-06 20:15:24 補充:
logx/loga>x²
logx<0,x²>0,loga<0
logx
x^(1/x²)
y=x^(1/x²)
dy/dx=(1-2lnx)[x^(1/x²-3)]=0
x =√e
0
0
2012-08-06 20:15:57 補充:
0 < x ≦ 1/2
a > 0
2012-08-06 20:21:24 補充:
logx < x²loga
a > x^(1/x²)
2012-08-06 20:23:02 補充:
改好答案
唔好意思,有四行爛咗
2012-08-08 07:21:44 補充:
a > 0 and loga < 0
0<1
2012-08-08 07:22:09 補充:
0 < a < 1
2012-08-08 07:36:57 補充:
logx/loga > x²
logx < 0,x² > 0,log a < 0,a < 1
logx < x²loga
a > x^(1/x²)
y=x^(1/x²)
dy/dx=[x^(1/x²-3)](1-2lnx)=0
x=√e
0 < x ≦ 1/2
0 < a < 1