Question

if x-1/x=4thwn the value of x^2+1/x^2=_____
a....16
b....18
c....14
d....12​

Answer 1

Answer:

$\large\bold\red{(b)18}$

Step-by-step explanation:

Given,

$x - \frac{1}{x} = 4$

Squaring both the sides,

we get,

$= > {(x - \frac{1}{x}) }^{2} = {4}^{2} \\ \\ = > {x}^{2} + \frac{1}{ {x}^{2} } - 2 = 16 \\ \\ = > {x}^{2} + \frac{1}{ {x}^{2} } = 16 + 2 \\ \\ = > {x}^{2} + \frac{1}{ {x}^{2} } = 18$

Hence,

Correct Option is (b) 18