Question

If x+1/x = root 7 find the value the value of x^4+1/x^4

Answer 1

Answer:

23

Step-by-step explanation:

$x+1/x=\sqrt 7\\(x+1/x)^2 = 7\\x^2+1/x^2+2=7\\x^2+1/x^2=5\\(x^2+1/x^2)^2=25\\x^4+1/x^4+2=25\\x^4+1/x^4=23$