SSC CGL Model Paper 18

© examsiri.com

Question : 62 of 100

Marks: +1, -0

If

x = √{{2+√3}/{2-√3}}

, then what is the value of

x ^2 + x -9

?

0
$3√2$
$3√3$
$5√3$

Solution:

x = √{{2+√3}/{2-√3}}

x = √{{2+√3}/{2-√3}×{2+√3}/{2+√3}}

⇒

x = √{{(2+√3)^2}/{4-3}}={2+√3 }/1

⇒

x = 2 + √3

∴

x^ 2 + x -9 = (2 + √3)^2 + 2+ √3 - 9

=4 + 3 +4√3 - 7 + √3

=5√3

© examsiri.com

Go to Question:

Prev Question

Next Question