If x = 1 + √2, then what is the value of x4 - 4x3 + 4x2 + 4?  Answers
A) - 1 B) 0 C) 5 D) 2 E) 3

Rationale: answer x = 1 + √ 2 ∴ x 4 - 4 x 3 + 4 x 2 + 5 = x 2 ( x 2 - 4 x + 4 ) + 4 = x 2 ( x - 2 ) 2 + 4 = ( 1 + √ 2 ) 2 ( 1 + √ 2 - 2 ) 2 + 4 = ( √ 2 + 1 ) 2 ( √ 2 - 1 ) 2 + 4 = [ ( √ 2 ) 2 - ( 1 ) 2 ] 2 + 4 = ( 2 - 1 ) 2 = 1 + 4 = 5 correct option : c
Answer: C