Question

Q16. Find x^2 + 1/x^2 , if x + 1/x = 3

Answer 1

Answer:

$2 \times x \times \frac{1}{x} = 2 \\ {x}^{2} + {y }^{2} + 2xy = {(x + y)}^{2} \\ {x}^{2} + \frac{1}{ {x}^{2} } + 2 = {(x + \frac{1}{x} })^{2} = {3}^{2} = 9$