## bakonloverk 3 years ago what is the multiplicative inverse?

1. anonymous
2. anonymous

are you asking for the definition?

3. anonymous

multiplicative inverse (mathematics) one of a pair of numbers whose product is 1: the reciprocal of 2/3 is 3/2; the multiplicative inverse of 7 is 1/7.

4. bakonloverk

ok wait wht is the multiplicative inverse of 5/7?

5. anonymous

the inverse of a number means that if you multiply the number by its inverse you will get 1. so therefore, to work out the inverse you do 1 divided by the number.

6. anonymous

7/5

7. bakonloverk

ohhhhhh ok thank u

8. skullpatrol

Do you understand now?

9. bakonloverk

yea i do

10. bakonloverk

wait so would the inverse of -2 3/4 be 4/11?

11. skullpatrol

|dw:1360271797991:dw|

12. skullpatrol

|dw:1360271859211:dw|

13. bakonloverk

wait im confused

14. bakonloverk

wait wait wait never mind

15. skullpatrol

You are missing the minus sign.

16. bakonloverk

oh so its -4/11?

17. skullpatrol

Correct. What is the multiplicative inverse of -1?

18. bakonloverk

1/-1 right?

19. skullpatrol

What does that equal?

20. bakonloverk

-1

21. skullpatrol

Correct, excellent. how about the multiplicative inverse of 0?

22. bakonloverk

wouldnt tht just b 0?

23. skullpatrol

Are you sure? Think about it....

24. bakonloverk

wait 1?

25. skullpatrol

26. bakonloverk

well im not trying 2 guess

27. skullpatrol

I know, I know.... sorry but this is one of THE most difficult questions to understand for most students, I apologize.

28. bakonloverk

wait it is 0

29. skullpatrol

A multiplicative inverse is also called a "reciprocal" as is DEFINED as so, reciprocals: Two numbers whose product is 1.

30. bakonloverk

0/1 would b 1/0

31. skullpatrol

|dw:1360273959086:dw|

32. bakonloverk

ohhhh so the answer is 1?

33. skullpatrol

No.

34. bakonloverk

ugh then wht is it?

35. skullpatrol

36. bakonloverk

omg thts wht my calculator said

37. skullpatrol

Let me show you the DEFINING equation for reciprocals again: $$a*b=1$$ When asked to find the reciprocal of a number replace one of the letters in this equation with that number and solve for the other letter, for example: what is the reciprocal of 2? So $$2*b=1$$ What number multiplied by 2 gives 1?

38. bakonloverk

0.5

39. skullpatrol

Correct.

40. bakonloverk

YAY!!!! i finally understand something

41. skullpatrol

What is the reciprocal of 0.5?

42. bakonloverk

1/0.5?

43. skullpatrol

Yes!!! simplify that please. What number multiplied by 0.5 equals 1?

44. bakonloverk

2

45. skullpatrol

Correct.

46. bakonloverk

kk give me another one

47. skullpatrol

What is the reciprocal of 0?

48. bakonloverk

wait we just did this one

49. skullpatrol

Follow the steps I gave you above.

50. bakonloverk

0 * b = 1

51. skullpatrol

EXCELLENT!!! Now you are really learning :-D

52. bakonloverk

lol so then it would b 1/0?

53. skullpatrol

$$\frac{1}{0}$$ is not a number, because division by 0 is undefined.

54. bakonloverk

well yea but if we were using different numbers would it look almost like tht?

55. skullpatrol

56. bakonloverk

like in the problem im doing now hold on

57. bakonloverk

$4\frac{ 1 }{ 8} would be \frac{ 8 }{ 33 }$

58. bakonloverk

right?

59. skullpatrol

Yes.

60. bakonloverk

YAY!!!!

61. skullpatrol

Let me try and explain why you can never divide by 0. Dividing by 0 would mean multiplying by the reciprocal of 0, but 0 has no reciprocal because 0 times ANY number is 0, NOT 1.

62. bakonloverk

OMG tht makes soooo much sense now

63. skullpatrol

|dw:1360276164935:dw|

64. bakonloverk

nope

65. skullpatrol

So what is the answer to "what is the multiplicative inverse of 0?"

66. skullpatrol

|dw:1360276813364:dw|

67. bakonloverk

there is no answer u cant put any number there

68. skullpatrol

Correct.

69. bakonloverk

yay omg thank u so much

70. skullpatrol

np :)

71. bakonloverk

:)

72. bakonloverk

wait can u help me with another problem?

73. bakonloverk

the smallest owl found in the united states is the elf owl, which weighs 1 1/2 ounces. one of the largest owls is the Eurasian eagle owl which weighs nearly 10 pounds or 156 ounces. the Eurasian eagle owl is how many times as heavy as the elf owl?

74. bakonloverk

thts the problem^^^

75. skullpatrol

Any ideas?

76. bakonloverk

well idk how 2 set the problem up

77. skullpatrol

Decide what unknown number is asked for and what facts are known.

78. bakonloverk

do i have 2 convert 1 1/2 into an improper fraction?

79. skullpatrol

Yes.

80. bakonloverk

ok so thts 3/2

81. skullpatrol

Correct.

82. bakonloverk

then do i put 156 over 1?

83. skullpatrol

Yes.

84. bakonloverk

so would it b $\frac{ 156 }{ 1 } - \frac{ 3 }{ 2 }$

85. skullpatrol

|dw:1360277686583:dw|

86. bakonloverk

oh so its 156 divided by 3/2?

87. skullpatrol

Yes.

88. bakonloverk

so its 312/3

89. bakonloverk

90. skullpatrol

Not ounces, but how many times heavier.

91. bakonloverk

ohhhhh kk thank u