arrow
arrow
arrow
Simplify: 21−2\frac{2}{1 - \sqrt{2}}1−2​2​​​
Question

Simplify: 212\frac{2}{1 - \sqrt{2}}​​

A.

-2(1 + √2)

B.

1- 2√2

C.

(2 + √2)

D.

2 + √2

Correct option is A

Solution:

Expression = 212\frac{2}{1 - \sqrt{2}}​​

Multiply numerator and denominator by the conjugate of (12):(1 - \sqrt{2}):​​

Expression = 2×(1+2)(12)×(1+2) \frac{2 \times (1 + \sqrt{2})}{(1 - \sqrt{2}) \times (1 + \sqrt{2})}​​

Denominator = (12)(1+2)=12=1(1 - \sqrt{2})(1 + \sqrt{2}) = 1 - 2 = -1​​

Numerator = 2×(1+2)=2+222 \times (1 + \sqrt{2}) = 2 + 2\sqrt{2}​​

Expression = (2+22)-(2 + 2\sqrt{2})​​

The simplified expression is 222. -2 - 2\sqrt{2}.  = -2(1+2\sqrt2)​

Free Tests

Free
Must Attempt

CBT-1 Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

RRB NTPC Graduate Level PYP (Held on 5 Jun 2025 S1)

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

CBT-1 General Awareness Section Test 1

languageIcon English
  • pdpQsnIcon40 Questions
  • pdpsheetsIcon30 Marks
  • timerIcon25 Mins
languageIcon English
test-prime-package

Access ‘RRB JE CBT-I’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
354k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow