设符号函数f(x)=sgnx={①1,x>0②0,x=0③-1,x

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设符号函数f(x)=sgnx={①1,x>0②0,x=0③-1,x
设符号函数f(x)=sgnx={①1,x>0②0,x=0③-1,x

设符号函数f(x)=sgnx={①1,x>0②0,x=0③-1,x
x+1={①x-2,x>0②1,x=0③1/(x-2),x0 x+1=x-2 => 1=-2 => ∅
②x=0 x+1=1 => x=0
③x+1=1/(x-2) => x^2-2x+x-2=1 =>x^2-x-3=0 => (x-1/2)^2-1/4-3=0 =>x=+-sqrt(13/4)+1/2
解集为 {0,-sqrt(13/4)+1/2,sqrt(13/4)+1/2}