Question

If x = 3 + V8 then x2 + 1 =

Answer 1

Step-by-step explanation:

Perhaps the question is:

$x =3+\sqrt 8$

If it is so then'

$x^2 =(3+\sqrt 8) ^2 \\</p><p>= 3^2 +(\sqrt 8)^2+2\times 3\times\sqrt 8\\</p><p>=9+8+6\sqrt {2 ^2\times 2} \\</p><p>=17+6\times 2\sqrt { 2} \\</p><p>=17+12\sqrt { 2}\\</p><p>\therefore x^2 =17+12\sqrt{2} \\</p><p>\implies x^2+1 =17+12\sqrt{2}+1\\</p><p>\implies x^2+1 =18+12\sqrt{2}\\</p><p>\implies x^2+1 =6(3+2\sqrt{2})$