-x^3+x^2-x-1=0....-(x^3+x)+(x^2+1)-2=0....(x^3+x)-(x^2+1)=-2... (x^2+1)(x-1)=-2....(3)
in 3rd equation multiplication of two terms is <0 ...it means one of them must be <0 ...but (x^2+1) . would always be >0...
i.e only (x-1) would be <0....x-1<0 ,x<1...this says that value of x will be less than 1....and (x^2+1) for x<1 will result the values less than 1...and multiplication of two number(less than 1..always results less than one...
therefor no value of will satisfied the equation?????