For x ≥ y 1 , let _x((x)/(y))+ _y((y)/(x))=k , then the value of k can never be equal to:

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For x ≥ y > 1 , let _x((x)/(y))+ _y((y)/(x))=k , then the value of k can never be equal to:

Quantrex Academy · Accepted Answer

Correct answer: D. 1

_x((x)/(y))+ _y((y)/(x))=k aligned & _x x- _x y+ _y y- _y x=k & 1- _x y+1-(1)/( _x y)=k & Let, _x y=t & 2-t-(1)/(t)=k & 2 t-t^2-1=k t & t^2+(k-2) t+1=0 & For solution, D=b^2-4 a c ≥ 0 & (k-2)^2-4 ≥ 0 (k-2)^2 ≥ 0 & k-2 ≥ 2 k-2 ≤ 0 & k ≥ 4 k ≤ 0 & k ≥ 4 or k ≤ 0 aligned Hence, k ≠ 1 .

For x ≥ y > 1 , let _x((x)/(y))+ _y((y)/(x))=k , then the value of...

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