Match List I (Question) with List II (Answer).
List I
i.If x + 1/x = 2, then (x - 1/x) = ?
ii.If x - y = 1 and x^2 + y^2 = 41 then x + y = ?
iii.If (1 - 1/x) = 2, then 1 + 1/x^2 = ?
iv.If (x - 1/x) = 3 then x^2 + 1/x^2 = ?
List II
a.11
b.2
c.0
d.Plus or minus 9
Ai-a, ii-c, iii-d, iv-b
Bi-a, ii-b, iii-c, iv-d
Ci-b, ii-c, iii-a, iv-d
Di-c, ii-d, iii-b, iv-a ✓ Correct
Correct answer: (D) i-c, ii-d, iii-b, iv-a
Explanation
The matching is i-c, ii-d, iii-b, iv-a.
x + 1/x = 2 gives x = 1, so x - 1/x = 0.
(x+y)^2 = 2(x^2+y^2) - (x-y)^2 = 82 - 1 = 81, so x+y = plus or minus 9.
1 - 1/x = 2 gives x = -1, so 1 + 1/x^2 = 2.
x^2 + 1/x^2 = (x - 1/x)^2 + 2 = 9 + 2 = 11.
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