Ratio test | Series | AP Calculus BC | Khan Academy

The ratio test is a most useful test for series convergence. It caries over intuition from geometric series to more general series. Learn more about it here.

AP Calculus BC on Khan Academy: Learn AP Calculus BC - everything from AP Calculus AB plus a few extra goodies, such as Taylor series, to prepare you for the AP Test

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[caseycrown]

"this isn't some voodoo" actually made me laugh out loud. Love you Sal!

[cagneymoreau]

sal: this isn't voodoo

everyone: actually it is

[krishnashah]

Thank u so much....Now i can literally Visiulize the Seriea🤩🤩♥️

[NotoriousJ]

6:45 "yes we can" sounded like Obama lol 😭

[najeebkaraye]

tank you very much sir,
you make it easy to understand.

[RiaziMohandesi]

What about harmonic series? It's a divergent series. 1+ 1/2 + 1/3 + 1/4

[farhansyed]

Can you make videos on English like vocabulary and grammar

[bw]

You can't prove that n^10/n! doesn't diverge with the divergence test as stated in 2:40 because lim an = 0 so it can still diverge ou converge. Or am I wrong?

[erikmoe]

Shoutout to Ms. Swish! Loved your PE classes. Keep on surfin' and catchin' those mavericks!

[owenzhu]

how many of you watching this in college

[leguminosa]

what happen if the limit of (n+1)th term over nth term doesn't approach to any value? We simply cannot use Ratio Test, can we?

[DeannaBoneman]

Do you have videos that teach like other subjects a and languages?

[abdullahsiddiquesiddique]

Tell me k hmy kesy pta chly ga k is question ma kon sa test use hona hy?

[amanmahendroo]

1:40 I feel that if abs(r) = 1, the series STILL converges to the first term

[rashmikababajee]

how do we decide when to write n=5, n=1 or n=0? I am kind of confused :S

[Ari-xhnr]

Can’t watch this man at less then 2x speed lol

[cmdrbobert]

I'm afraid I still cannot tell what it happening when you say that n is going to infinity. If n becomes infinity in both the denominator and the numerator of a fraction, isn't it just going to converge at 1 regardless?

[pepsico]

I thought the ratio of a geometric series was An/An-1?

[maerkforbes]

In every Khan academy video he verbally repeats any text he is writing several times and it drives me fucking crazy

[DmitriNesteruk]

You might want to consider avoiding the hand as the pointer - it is severely distracting!