Why is the answer A and not D?
(x+1/x)^2 = x^2 + 2 + (1/x)^2
(x+1/x)^2 = x^2 + (1/x)^2 + 2
(x+1/x)^2 = 7 + 2
(x+1/x)^2 = 9
Taking Square root
Either, x+1/x = 3
or, x+1/x = -3
Why is the answer A and not D?
(x+1/x)^2 = x^2 + 2 + (1/x)^2
(x+1/x)^2 = x^2 + (1/x)^2 + 2
(x+1/x)^2 = 7 + 2
(x+1/x)^2 = 9
Taking Square root
Either, x+1/x = 3
or, x+1/x = -3
Hint: x is positive.
Thanks. Got it Now.