Question


A.

1

B.

–1

C.

0

D.

–2

Correct option is A

Given:

x+1x=1x + \frac{1}{x} = 1 ​​

Formula Used:  

a3+b3=(a+b)(a2+b2ab)a^3 + b^3 = (a+b)(a^2 +b^2 - ab) 

Solution:

x+1x=1​x + \frac{1}{x} = 1   

x2x+1=0x^2 - x + 1 = 0​​

x3+13=(x+1)(x2x+1)=0x^3 + 1^3 = (x + 1)(x^2 - x + 1) = 0​​

x3=1x^3 = -1

Then the value x12+x9+x6+x3+1x^{12}+x^9 +x^6 +x^3 +1​​

Thus,  x9(x3+1)+x3(x3+1)+1=1x^9 (x^3 + 1) + x^3 (x^3 + 1) + 1 = 1​​

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