Question

Given: f(x) = X^2-x
evaluate: f(sqrt2 + 3)
I have worked out this and am stuck:

(sqrt2+3)^2 - (sqrt2+3)
(sqrt2+3)*(sqrt2+3)- (sqrt2 +3)
(sqrt2)^2+ 3sqrt2 +3sqrt2+ 9- (sqrt2+3)
2+6sqrt2 +9-sqrt2-3
and am stuck or wrong here. Ans= SQRT2+6sqrt2 all under radical

Answer 1

(sqrt2+3)^2 - (sqrt2+3)
let a = sqrt 2 so a^2 = 2
(a+3)^2 - (a+3)

a^2 + 6 a + 9 - a - 3

a^2 + 5 a + 6

2 + 5 sqrt 2 + 6

8 + 5 sqrt 2

Answer 2

THANKS!!