Akshay_Budhkar 4 years ago A bit of tricky question on complex numbers.. try it guys for fun.. What are the answers to 1.√(-1 * -1) and 2.√(-1)*√(-1) a.1 b.-1....

1. Raioner

1. 1

2. Raioner

2.1i^2=-1

3. Akshay_Budhkar

myininaya i wanted others to answer it.. lol!!!

4. myininaya

oops i can delete

5. myininaya

lol

6. Raioner

myinaya can you take a look at my problem i had a couple days ago?

7. myininaya

sure is it a quick one i have to go to bed

8. Akshay_Budhkar

Raioner give the link.. even i will give a try

9. Raioner
10. Akshay_Budhkar

11. joemath314159

i feel like its a trap >.> lol

12. Akshay_Budhkar

13. joemath314159

isnt the first one 1 and the second one -1? or am i not giving this problem the attention it deserves?

14. myininaya

joe its not a trap

15. Akshay_Budhkar

i made it look like a trap.. lol!! ur right

16. Alchemista

I don't really understand how it is tricky? This is just order of operations and complex numbers.

17. joemath314159

Alchemista, nothing is tricky to you!

18. myininaya

lol its not tricky it wasn't meant for us people who have already passed algebra

19. Akshay_Budhkar

well ppl can answer the second one as 1 too as Raioner did in the first reply... @Alchemista

20. myininaya

yea raioner did a good job :) go raioner!

21. joemath314159

i dont know what im doing up <.< i have class tomorrow morning >.>

22. myininaya

i said gn and im still here

23. Alchemista

I haven't seen any linear algebra on here for a while

24. Akshay_Budhkar

oh...

25. joemath314159

ive noticed too Alchemista, and it saddens me =/

26. Akshay_Budhkar

you mean to say questions on linear algebra?? @Alchemista

27. Alchemista

yes

28. joemath314159

maybe during the fall semester it will pick up? maybe the actual Linear Algebra 18.06 thread will be alive?

29. joemath314159

i can only dream~

30. Alchemista

and there certainly isn't any abstract algebra stuff

31. myininaya

ok here is an easy linear algebra problem: show that a n by n matrix with zeros everywhere except on the diagonal of the matrix has the diagonal entries as eigenvalues

32. Akshay_Budhkar

if u want i can ask you guys some questions by tomorrow..But i believe the others must ask... We can ask them to ask such questions...

33. myininaya

i know its easy but u wanted a linear algebra problem lol

34. myininaya

whats that matrix called a diagonalized matrix?

35. myininaya

i cant remember the name

36. Alchemista

It is a diagonal matrix

37. myininaya

ok lol

38. joemath314159

i still havent answered that one problem i asked a while back. I was able to prove that if A is an invertible matrix with integer entries, and its inverse also has invertible entries, then the det A must be 1 or -1 (as per Alchemista's suggestion, thank you again). But i dont see how to use that fact to solve the problem.

39. joemath314159

Had to prove it before I could use it anywhos.

40. myininaya

ok i must really go to bed gn

41. joemath314159

lates :)

42. Akshay_Budhkar

gn.. meet you tomorro

43. Akshay_Budhkar

joe u also leaving?

44. joemath314159

i really need to =/ i have less than 8 hours till class, gotta get some sleep >.<

45. Akshay_Budhkar

oh ok...

46. Akshay_Budhkar

bye...

47. joemath314159

is this your normal time frame? during the week i should be on around now for a while. Mondays are the only days where my sleep schedule is off lol.

48. Akshay_Budhkar

how did myininaya factorize ths 25x^2-2576x+9904???

49. joemath314159

jesus O.o the polynomial is ridiculous

50. Raioner

\[25x^{2}-2576x+9904\]

51. joemath314159

if it was me, i would have just went to wolframalpha.com to see what the roots are.

52. Akshay_Budhkar

Raioner wants it ..... i would have done the same.. lol!

53. joemath314159

wait....9904...is that something squared? maybe.....

54. Alchemista

\[(x-4)(25x-2476)\]

55. joemath314159

nope its not.

56. Raioner

how did you do that alchemista?

57. Akshay_Budhkar

yup thats what she got... how did u do that Alchemista?

58. Alchemista

There are many ways you can find the roots (factoring is one of them). You can complete the square or use the quadratic formula.

59. joemath314159

mathemagic...lolol i saw someone post this word yesterday.

60. Raioner

o pellet yea ax^2+bx+c

61. Akshay_Budhkar

yup she asked y mathematics was called mathemagic.

62. Raioner

didn't even think of that. brilliant. Thanks man.

63. Alchemista

There actually is something called "mathemagics" well its someone who performs quick mental computations using mnemonic devices.

64. Raioner

Thanks guys. time for bed.

65. Akshay_Budhkar

mnemonic devices. whats that?

66. joemath314159

sounds interesting o.O i might have to google that sometime. Lates Raioner.

67. Alchemista
68. Akshay_Budhkar

joe less dan 7 hours left for ur class.. lol!!!

69. joemath314159

lol >.< no idea why im up :)

70. joemath314159

that was amazing o.O