函数y=根号下log10(x^2-x-1)的定义域是?

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函数y=根号下log10(x^2-x-1)的定义域是?

函数y=根号下log10(x^2-x-1)的定义域是?
函数y=根号下log10(x^2-x-1)的定义域是?

函数y=根号下log10(x^2-x-1)的定义域是?
y=根号下log10(x^2-x-1)的定义域是
log10(x^2-x-1)>=0
真数:x^2-x-1>0
log10(x^2-x-1)>=0
x^2-x-1>=1
(x-2)(x+1)>=0
x>=2,x0
(x-1/2)^2>5/4
x>1/2+根号5/2,X

由题意,log10(x^2-x-1)>=0,所以x^2-x-1>=1恒大于0,即x>=2或x<=-1即为所求