SarkariPYQ

SSC CGL 2016 PYQ — Question 28

SSC CGL Tier II Quant - 30/11/2016 • Quantitative Aptitude • Q28

Back to paper

If x + 1/x = √3 the value of x18 + x12 + x6 + 1 is

Show answer & explanation

Correct answer: A

Explanation

The correct answer is option 1 i.e. 0

x + 1/x = √3 

cubing both sides, we get

⇒ x3 + 1/x3 = 0

⇒ x6 = -1

Now, 

x18 + x12 + x6 + 1

= ( x6)3 + ( x6)2 +  x6 + 1

= -1 + 1 - 1 + 1

= 0