Question
Solve `(x^2 + 1/x^2) - 3(x - 1/x) - 2 = 0`
Solution
`(x^2 + 1/x^2) - 3(x - 1/x) - 2 = 0`
Let `x - 1/x = y` squaring on both sides
`x^2 + 1/x^2 - 2 = y^2`
`=> x^2 + 1/x^2 = y^2 + 2`
Putting these values in the given equation
`(y^2 + 2) - 3y - 2 = 0`
`=> y^2 - 3y = 0`
=> y(y - 3) = 0
if y = 0 or y - 3 = 0
then y = 0 or y = 3
`=> x - 1/x = 0` or `x - 1/x = 3`
`=> (x^2 - 1)/x = 0 or (x^2 - 1)/x = 3`
`=> x^2 - 1 = 0 or x^2 - 3x - 1 = 0`
`=> (x + 1)(x - 1) = 0 or x = (-(-3) +- sqrt((-3)^2 - 4(1)(-1)))/(2(1))`
=> x = -1 and x = 1 or `x = (3 +- sqrt13)/2`
Is there an error in this question or solution?
Solution Solve (X^2 + 1/X^2) - 3(X - 1/X) - 2 = 0 Concept: Quadratic Equations.