Question

If x is equal to 3 + root 8 find the value of x square plus 1 by x Square

Answer 1

x=3+roots 8

1/x=1/3+root 8

1/x=1/3+root8 ×3-root8/3-root8

1/x=3-root8 /(3)^2-(root8)^2

1/x=3-root8 /9-8

1/x=3-root8

x+1/x=3+root8+3-root8 (root 8 will

cancel out)

x+1/x=3+3=6

squaring both sides

(x+1/x)^2=6^2

x^2+(1/x)^2+2×1/x×x=36 (x will cancel out

x^2+(1/x)^2+2×1=36

x^2+*1/x)^2=36-2

=34