Change of base formula | Logarithms | Algebra II | Khan Academy

Change of Base Formula

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[amywelsh]

Dear Sal Khan, My name is Amy Dewe-Mathews. I'm 45 years old and I'm back in school for Nursing. By trade I'm a hairdresser, which I've done for the last 28 years of my life. After my divorce, 5 years ago, I knew I needed a change, let alone a challenge! My passion has always been to make people feel so Nursing was a given. While earning my degree, I had to take intermediate Algebra. I couldn't pass to save my life! I dropped out and started working in a salon again. Then, a friend recommended I transfer to a different SchooL. So, I enquired and before I knew it I was enrolled and taking classes. I saw that here, I would not only have to take Intermediate Algebra, but College Algebra!!!! ARE YOU KIDDING I knew it was over before it began. Then You Entered MY Life!!!! Not only did I receive a B in Intermediate Algebra, I'm On my way to getting a B in college Algebra. What Khan Academy has done for me is monumental. But here's the kicker! Forget about the fact that I can now fulfill my I was watching CBS This Morning just now and as soon as I heard that voice I sat up and starting crying. It was so beautiful for me to put a face to the voice I've been hearing for the last 4 months. You helped me pass these courses and I NEED you to know what you're doing is not only detrimental but so caring valuable. I know I couldn't have passed these courses without you and I want to say Thank You. You're compassion is sorely needed in this world, esp. now.

[פרופסוראור]

you're doing it again!! 
simplifying all the calculus material and somehow making it all clear! I can't thank you enough for your help :)

[sunkissedtortoise]

I love how he doesnt just show how to do it, but he shows why it works. This helps me understand so much better! At 6:37 my mind was b l o w n

[aurorabtwCS]

use macro keys to change colours quickly, and will be able to stay faithful to colours fast.

[SteveLPDNB]

I like the was you say "C'th power" - Say it really angrily then you can seethingly seeth the word "C'th"

[MsPaigeKat]

This is great; thank you so much. I have a test today, and was feeling totally unprepared because my teacher ran out of time and had to rush through this entire lesson in about 5 minutes. Now I know what's going on, though. Thanks!

[denissemitchell]

great video! gosh thank you thank you thank YOU! I can sense the passion between you and mathematics. This is why we should follow our passions... the energy spreads.

[talhahasan]

Brilliantly explained Sir, I definitely owe you one.
(Well actually I owe you many)

[nozzerjuice]

you should be the narrator on shows about the universe.

[nightskiesburialground]

Thanks! I have a test today and this helped to refresh my understanding.

[bunnii]

I love every time my professor posts a Khan academy video and I hear this voice! Speaks so clear and I love when he repeats his steps!

[strawberry.teacake]

Thank you so much. This really helped me prepare for my math test as I have a bad teacher and no one else to properly explain things to me. I am so grateful for your videos :)

[TroutSniffer]

You can change the base using that calculator. Use parentheses, and a comma to separate the base. such as log (x+2), 4. or even approx ((log ((x+2), (5))÷log ((x-3), (2))). Most scientific calculators I have used for logs, have this funtion.

[bradjkirwan]

Good job Sal, just in time for my Math exam next week :)

[nikhiltripathi]

Sal is epic!! nd the derivation is awesome

[elijah_]

I don’t know what I would do without you in my life 😩

[sotash]

I love the calculator graphic!!! VERY helpful!!!

[aninditakundu]

This channel made my change of base rule for logarithm much much clear

[abdulazezalshammari]

Thanks for making youtube great and useful 👌🏼

[lexinaut]

 Nice and clear!  And now a base logarithm joke.  "Great Scott!  Napier was an exponent of logarithms!"  John Napier, a Scottish fellow, logged in with a book explaining logarithms in 1614. Logarithms speeded up various calculations done by hand greatly, thus speeding up mathematical and scientific progress. Logarithms are empowering even if sometimes it seems like they are glowering! Time to log out!