If$$x^4$$​+1/$$x^4$$​ = 6239, and x > 0, then the value of x + 1/x is:

Correct option is A

Given:

​$$x^4$$​​+1/$$x^4$$​​= 6239

Formula Used:

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

Solution:

​$$x^4$$​​​+1/$$x^4$$+2= 6239+2

($$x^2+\frac{1}{x^2}$$​)$$^2$$=6241

$$x^2+\frac{1}{x^2}=$$79

2+$$x^2+\frac{1}{x^2}=$$79+2

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

(x+$$\frac{1}{x}$$​​)$$^2$$ =81

​$$x+\frac{1}{x}$$ =9​

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