GATE CSE
First time here? Checkout the FAQ!
x
+1 vote
63 views

After taking |A|=0, I am getting x3+1=0 and not x3-1=0.
Is it x3+1=0 or x3-1=0?

asked in Mathematical Logic by Loyal (3.6k points)   | 63 views

1 Answer

+1 vote
Best answer
|A| = x * ( x*x - 0 ) - (-1)(0 - (-1)(-1)) = 0 [expanding along the first row and |A| should be 0]

=> $x^3 - 1$ = 0

=> x = 1
answered by Loyal (3.3k points)  
selected by

Ya, i missed the '-' in multiplying 2nd parameter.

BTW, expansion of (x3-1) is (x-1)(x2+x+1), so x=1, and not -1, for real values of x. 

Oh, sorry, that's a typo :P editing the answer.


Top Users May 2017
  1. akash.dinkar12

    3140 Points

  2. pawan kumarln

    1606 Points

  3. sh!va

    1580 Points

  4. Arjun

    1316 Points

  5. Devshree Dubey

    1230 Points

  6. Angkit

    1020 Points

  7. Debashish Deka

    1012 Points

  8. Bikram

    970 Points

  9. LeenSharma

    796 Points

  10. srestha

    658 Points

Monthly Topper: Rs. 500 gift card
Top Users 2017 May 22 - 28
  1. pawan kumarln

    232 Points

  2. jjayantamahata

    106 Points

  3. joshi_nitish

    106 Points

  4. Ahwan

    96 Points

  5. Aditya GN

    63 Points


22,717 questions
29,045 answers
65,029 comments
27,454 users