Question

If x is equals to 9 minus 4 root 5 find the value of x square + 1 by x square

Answer 1

Step-by-step explanation:

x=9-4√5

1/x=1/9-4√5

=(1×9+4√5)/{(9-4√5)×(9+4√5)}

=9+4√5/(9)^2-(4√5)^2

=9+4√5/81-80

1/x =9+4√5

x+1/x=(9-4√5)+(9+4√5)

=9-4√5+9+4√5

=18

(x+1/x)^2=(18)^2

x^2+2×x×1/x+(1/x)^2=324

x^2+1/x^2=324-2

x^2+1/x^2=322