Question

if x=3/√8 then find x^2+1/x^2​

Answer 1

Given :-

x = 3/√8

Therefore x² = (3/√8)²

= (3 × 3)/(√8 × √8)

= 9/8

And 1/x² = 1/(9/8)

Hence, value of x² + 1/x² :-

= 9/8 + 1/(9/8)

= 9/8 + 8/9

Taking LCM of 8 and 9, we get

= (9 × 9)/(8 × 9) + (8 × 8)/(9 × 8)

= 81/72 + 64/72

= (81 + 64)/72

= 145/72 Final answer!

Answer 2

$\large{\mathfrak{\underline{\underline{Answer :-}}}}$

Given :-

x = 3/√8.......[1]

✯ To find x² will square both side in equation 1.

x² = (3/√8)

⇒x² = (3 × 3)/(√8 × √8)

⇒x² = 9/8.........[2]

✯ To find 1/x² we will do reciprocal of equation 2.

1/x² = 1/(9/8)

_________________[Putting values]

⟹ x² + 1/x² :-

⇒ 9/8 + 1/(9/8)

⇒ 9/8 + 8/9

✯Taking LCM

⇒ (81 + 64)/72

⇒ (145)/72

$\huge{\sf{\boxed{\boxed{\frac{145}{72}}}}}$