Question

Why (x-1/x)^2= x^2+1/x^2-2?? Why there -2 at the last? Please answer this. Exam today.

Answer 1

Answer:

Step-by-step explanation:

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Answer 2

$(x - \frac{1}{x} ) {}^{2} \\ \\ = x {}^{2} + \frac{1}{ {x}^{2} } - 2 \: (x) \: ( \frac{1}{x} )$

(a - b)² = a² + b² - 2 a b.

The x'es get cancelled, rendering a -2 there.