Q468
If x = 2 + √3, then find the value of x4 - 8x3 + 16x2.
A.
-1
B.
1
AnswerC.
0
D.
2
Answer: Option B
Solution
Answer: Option B
Solution:
x = 2 + √3x2 = 7 + 4√3
x4 - 8x3 + 16x2
= x2(x2 - 8x + 16)
= x2(x - 4)2
= (7 + 4√3)(2 + √3 - 4)2
= (7 + 4√3)(2 - √3)2
= (7 + 4√3)(7 - 4√3)
= 1