# Logarithms | Logarithms | Algebra II | Khan Academy

## 100 thoughts on “Logarithms | Logarithms | Algebra II | Khan Academy”

1. LoveHateSerendipity says:

Your voice sounds like a story teller in this video. happy holidays Sal–

2. Jai Kotia says:

I had logarithms last term and I thought it was easy. Not anymore.

3. Abi says:

Can you have logarithms with negative or imaginary numbers?

4. Michael McNeil says:

What an inept teacher.
And boring.

5. Leon Jarabek says:

EXCEPT 0!

6. Thomaxonal says:

Except 0 what?

7. Hiroshima says:

You can power any number with 0 EXCEPT 0 because 0 at power 0 does not make any sense

8. Leon Jarabek says:

dude, you can't raise 0 to the power of 0.

9. Thomaxonal says:

When did I say we could?

10. Satan's Apple Dandies says:

You are probabley a teacher yourself.

11. B- Rand says:

Holy Crap thank you so much, you're a really good teacher, and color coding it was very helpful, I couldn't undertand it cause my teacher made it sound so complicated. Thanks again, for sharing!

12. CompleteRandomness22 says:

I'm sad that this was so simple. I really wish I had found this specific video when I was taking algebra in high school. I actually still couldn't remember logarithms (nor did I understand it at all). You made this very simple. My teacher was horrible the way she explained it and the way the class was taught was that we were put in groups. In high school, groups don't get ANYWHERE in learning. I hope I made sense lol

13. Ghost572 says:

Thats high school in general, i learned jack there because of the way they taught it. they just recycle the same shitty was to explain it on the way they taught it and if you don't get it then thats it you miss out. its nice now that we have plenty of options to learn.

14. Danny says:

This was way easier than I thought.. And I suck at math. HOW did I understand this?

15. Tony Stark says:

Is there any way to solve logs without a calculator. I'm thinking that there must be. And I'm not talking about something like log base 2 of 8 or log base 2 of 16. Those are simple cuz the answers to those are whole numbers: 3 and 4. I'm talking about something like: log of 2. The answer to that is about 0.301… I solved this through a calculator. How can I do it from scratch?

16. Pawel X says:

Whst is log base 1 of 1? Is it 1 or 0, or both?
(1^1=1 AND 1^0=1)

17. OFBoi says:

Ahhh, I love you Sal!

18. Christopher Moore says:

This man is a saint.  What a wonderful time we live in where a guy like Mr. Khan is kind enough to share his intellect and teaching ability on the miracle that is the internet so people like me can learn in 2 minutes what an entire expensive 3 hour college algebra lecture failed to do.  Thank you, sir.  It's people like you that make the world go 'round.

19. RPDBY says:

maaan, I always used to think about logarithms as of somethings mysterious and completely incomprehensible, but 2 minutes of this this video completely changed it

20. JohnOriginal says:

Hmm why is there no sound, and why are the subtitles in Czech?

21. toksikologija123 says:

You are a god !

22. glitterintheairxoxo says:

These videos have made studying for the ACT so much easier. Thank you Sal!

23. disdat says:

ٌYou're amazing Sal you made it so simple !! 😀

24. Preston Siegler says:

I'm a homeschooled student who's always had problems with math,but the kahn Academy site and videos have really helped me improve and actually like math(something I thought I'd never say!). To the creator of Kahn Academy,thank you.

25. Chan Sunny says:

I've been stuck when doing log for days until watching this detailed video 🙂 Thx'a lot

26. jV says:

you were sent to this earth for a reason lol

27. meep says:

Hey guys, what grade are you in when you learn this?

28. Ricky Monterrosa says:

You sir explained in 7 mins what my professor  couldn't explain in 20. Thank you !

29. CoDRagna says:

wtf i dont want to do no guess and test method, teach me how to solve completely random ones like log base 3 (1230193013)

30. Raylo says:

Wow I should pay you to be my teacher. I have a really shitty math teacher as a senior and I have suffered pretty much all year because of this crappy teacher who can't teach. She just skips most of the steps and whenever you go up and ask something specific that requires prior knowledge(hello, people forget..), she just says you should have learned this from last year and then she refuses to help. My pre-calc teacher needs to be fired! She is horrible!

Thanks Mr. Khan/Sal you are an amazing teacher. You should make money off of this because you are helping so many people around the world in a few minutes whereas shitty math teacher can't over the course of an year

31. NNJAx says:

Reviewing for college placement exams, really helped refresh my memory. thanks!

32. Sunay Rastogi says:

GG m9

33. whattsy320 says:

you are the best!

34. Eonix says:

I`m 18, and I understand this (Only because your a SUPER-AWSOME TEACHER!!!!!!!!!!!) !!

35. Anime Fanatic says:

BORING!!!!!!!!!!!!!

36. Holli Lyndora says:

can someone please explain how 16 is the power? Other sites are saying the 4 would be the power–or the exponent, but nobody is assigning the power to the number in the 16's position. It makes no sense to me…but i admit I am struggling with this.

This is from the intro to logarithms text page after the video.
24=16⟺log2(16)=4
Both equations describe the same relationship between the numbers 2, 4, and 16 where 2, is the base, 4 is the exponent, and 16 16 is the power.

37. Koko N says:

thanks you so much. I am struggling with change of base

38. FireStream says:

Is there an easier way to evaluate logarithmic expressions WITHOUT creating some sort of factorization tree or running through a "guess and check" / "trial and error" method?

For instance, there are defined processes with guidelines to add, subtract, multiply, and divide large numbers. How would I quickly evaluate a logarithmic expression that I do not have "memorized"?

This video is one of the more popular YouTube video on logarithms, so please upvote this comment to let all of the wandering math majors and wizards see this comment.

39. Wahdat Afroz Khan says:

good

40. Clay Banks says:

Are we not gonna talk about how much this guy sounds like Chris Griffin?
But seriously, thank you for this

41. Ryan Brown says:

42. sak sezo says:

Holy fuck dude? i understood in 7 mins , took me 3 years in high school struggling to understand wtf is log , i blame stupid teachers who work inefficiency for money

43. woh says:

i had testicular aids and my great uncle was diagnosed a coconut but after i saw this video, my jellybeans turned green

44. Isabella Amelia says:

When it makes sense then you realize this video is before common core

45. Aayush K Thakur says:

46. Prince Kumar says:

value of log 10 ka power 7

47. Saphira Winters says:

you should have done log base 5 of x equals 4.

48. ohh says:

not gonna lie, you got me on the last one.. great lesson.. I will say when you said, ok let's try another one, I was like NOOOOOOOOO:) I know you have to practice and take notes to get any subject.. math is no different.. thanks again!!

49. sciencified Human says:

thats it? thats all it is? i was afraid of this my whole life?

good video Mr khan I subscribed

51. Jessica Amy Brandt says:

Thank you soo much 💕🙏🙏please do calculus with language

52. Ludovico Calvetti says:

Am I the only one who thinks Mr. Khan sounds like the Rock?

I'm in 8th grade and man there still teaching how to solve inequalities and equations

Like damn they think we're stupid

This is easy af and I'm sure teachers in my junior year (future) would take 5 months reviewing algebra 1 and the rest of the year doping around

54. Djentleman says:

This should be in schools, god knows teachers can't explain it.

55. alexa play BTS says:

This is by far an AMAZING asmr!

56. Byron JONES says:

such a great teacher

57. Cassidy Wagner says:

OK what about (log base 3) 82 = x?

58. Max says:

Tity? 6:16

59. Zulfiqar 729 says:

Thank you so much! I have my exam soon and our teacher hated every one of us and explained absolutely terribly. I didn't understand this chapter throughout the entire year and you've finally helped me understand it IN 7 MINUTES. Our teacher couldn't do it in a year!

60. Facehunter2003 says:

How do you solve them though?? Without a calculator

61. Angelique Schuster says:

I got stuck on logarithm in high school, now my youngest son in 4th grade knows about it. I always had to just turn into the back of the book to find the logarithm, not understanding anything I was doing. Wow…simple and precise. Thanks Mr. Kahn.

62. TOM JEFTA Banda says:

thank so much you a good teacher

63. Svensk Gamer says:

Thanks 500,000,000,000 times!

64. USHA K.S. says:

Thanks

65. Hi Hi says:

log . .zip

66. Datguy Phil says:

Help log4^8

67. sandilya kambhampati says:

thank you so much Mr.Khan .Its very helpful.

68. Gabriel Lima says:

69. Jay K. says:

Press [F] to pay respects

70. Hodo Abubakar says:

I Only heard of logarithms n I already understood it now
Wow😍😍😍
Thanks Sir Khan

Algebra is not magic…

72. Leo Rhett Gutsman says:

Good job.

73. Zohirul Islam Jewel says:

2:24–2:32 tells you all that you need to know.

why the hell this person tells how it works in a simple basic words while teachers are saying some mysthical words we forget

75. Matthew Quispe says:

What Logarithms used for in real life?

76. AMagical Twinkie says:

I’m currently learning geometry so I don’t understand why understand this so well wow khan is a legend

77. Hêllgûy says:

4:30 illuminati confirmed

78. raphael gako says:

You single?

79. Jay D says:

The last actually tricked me and disappointed me, I didn't think of 0

80. How to Do Stuff with Ethan says:

loglog=error 1 according to my calculator

81. LONG STUDIOS says:

Does Khan academy belongs to Pakistan

82. Vivian Z says:

I’m failing algebra 2 😭 hopefully I can learn everything online bc I’m currently not able to learn anything in class.

83. Dundershock says:

I was interested in learning this after my teacher in alg 1 class used his calculator and it showed a bunch of logs… actually seems pretty simple

84. Una Ex Gachatuber says:

M-ental
A-buse
T-o
H-umans

85. shravya reddy says:

You are the best! Bless your soul

86. SiR GriNdeR says:

Is it me or does Sal sound like Jack black 😂

87. sganime96 says:

nice

88. Sam Carmen says:

Thanks a lot!

89. JJ Supreme says:

I shall sleep less STUPID now….

90. Coral McNaughton says:

Khan, you saint.

91. Eathan Schlueter says:

this guys handwriting with the mouse tho

92. Nick Groenewegen says:

93. Rocc the Crocc says:

Watching 3 mins before my algebra 2 finals lmao

I still don't understand what the log button on my calculator does, when I type log (2)16 I get 4.8. Also what is happening when I just push log (5) = or any other number??? What happens when I log transform a data set?

Thanks for the video! Needed a little refresher and this brought my previous knowledge back. Khan Academy is amazing, thanks for making so much of math simple and understandable.

96. DANGY333L says:

can anyone help me? why all khan videos to me doesn't have a sound

97. Шамиль Ахмадов says:

Please tell me which program do you use to do all this stuff?

98. Seamus O'Dork says:

At 1:40 they are not totally equivalent statements at all. They might contain the same components but they are not equivalent.

99. Shymaa Shymaa says:

I just love how there are so many subtitles ❤️

100. The Truthful Channel says:

This helped me so much!! Thank you kindly. 🙂