If $ a^2 + b^2 + \frac{1}{a^2}+\frac{1}{b^2} = 4,$ a ≠ 0, b ≠ 0, then the value of $a^4 + b^4 $ is :
Answer & explanation
Correct answer: option 4
If $ a^2 + b^2 + \frac{1}{a^2}+\frac{1}{b^2}$ = 4
Put the values of a = b = 1
$a^4 + b^4 $ = $1^4 + 1^4 $ = 2