SSC CGL 2022 PYQ — Question 60

SSC CGL - 03 Dec 2022 - Shift 2 • Quantitative Aptitude • Q60

If  x=3+22,{{x=3+2\sqrt2,}}   x > 0, then the value of x−1x\sqrt x-{{1} \over \sqrt x} is :

Show answer & explanation

Correct answer: C

Explanation

The correct answer is Option 3 i.e. 2.

Calculations:

x=3+22,{{x=3+2\sqrt2,}}

Can be written as;

⇒ x = (√2)2 + 12 + 2√2

⇒ x = (√2 + 1)2

or

⇒ √x = √2 + 1 and 1/√x = √2 - 1

Hence, the required value of x−1x\sqrt x-{{1} \over \sqrt x}

⇒ √2 + 1 - √2 + 1 = 2