How to find the finite sum of a geometric sequence

[@Soonerman-sx6ey]

I haven’t understood a single thing in my precal class this entire year causing me to have to retest in almost every single test we have taken and I watch one video of yours and actually understand the subject. Thank you

[@brianmclogan]

You are welcome! Happy to help you out

[@Shinedown6479]

I'm only in 8th grade and understand sigma notation and sequences I just forgot what is was for a sum of a finite geometric series for anyone that needs to know sum of arithmetic sequences it's the the sum of n is the ace of 1 plus ace of n divided by 2 times n

[@litlabproductions2043]

Stick with it, I was in your shoes but even worse, a 21 year old in remedial math. Just enrolled in my 11th college math class a few days ago, Discrete Math II. 3 more to go until I'm done with it for my minor in mathematics and bachelor in Computer Science.

[@beko____]

Soonerman 2000 what does retest mean. Does your school let you take the same test more than once

[@bellaklein8692]

@@Shinedown6479 ayeee i was in eighth grade 2 years ago too XDDD age twin buddies hehe

[@Grace-yx4fk]

Brian, I am currently crying at the dinner table with my mom trying to review for my 1050 final. I CANNOT thank you enough. Ive basically forgotten everything from the past 7 units and you are really really saving me here. THANK YOU

[@justinjx3]

Man, if only all of my teachers actually cared about the students' learning. I would very much appreciate having a teacher like Mr. McLogan while the students in these videos are sort of being rude.

[@klav7974]

i wish u were my teacher ..... every year

[@kelvinj9720]

It feels good to see a teacher in quarantine

[@homer4590]

I'm in 8th grade (I'm not doing this math yet, I just find it interesting) and my middle school only has a regular and supplementary mathematics teacher. I'm in an advanced group. There are two advanced groups - computer learners, and group learners. I'm a group learner. The problem with this is that our teacher (she's a great teacher, but she's overwhelmed with all of the kids) doesn't have an opportunity to teach us and we are left learning from the book. The only thing we can do is ask questions t o specific problems. It's nice to have an actual teacher explain things to me because it truly does help.

[@hearnsleonard]

He both teaches and confuses me at the same time. I like how he has the formula there but that was so confusing to me it was much easier to evaluate each term seperately and then add the sum of them all. OVERALL i thank you, because you are the only reason im getting this homework done

[@winterrain1947]

yep, same with me. At first learning this, was easier for me to find all the terms. But that was 'only' when the examples needed a few terms.

[@Marg1312]

six years later and still helping!

[@maisonuga]

how is it that you are better at explaining math than any of the teachers i've ever had

[@sebastianbajescu4513]

quick question what is r?

[@kal.amansi1825]

Love this, finally understood it omg

[@hunterredwood5795]

Thank you, you really helped me a lot. My teacher cant teach through a computer so I'm honestly grateful

[@khaledmerhabi1881]

I cant thank you enough❤

[@1966lavc]

is that okay to use the shortcut formula? the first term divide by 1- r ?

[@dimund3942]

so the n=1, how does that relate to the actual sequence. you said its the start so that means the sequence starts at 1? but what if the rule is 4n-1 than 1 is the "one half" term. im confused on this matter how does n=1 relate to the actual sequence.

[@reignjericsabino2376]

How did he come up with the final answer? What did he do to 32(16380/12288) that is equivalent to 42.66???? ANSWER THESE PLEASE!

[@waynesullivant]

Uh. He was right. 32(16380/12288) is 42.66. Also 1365/32 is 42.66.

[@EpicSelenium34]

Hi thanks for this helpful video. In the geometric sequence where n = 1 is the start, n = 30 is the end and the rule is 5*(2/3), is 5 = a1? My answer key says that 5*(2/3) = a1. This seems wrong based on my knowledge and this video. Can someone clear this up please?

[@je_lly_ish_by_cc]

Thank you. It help me a alot

[@cocopie_]

This makes me sleepy

[@chefoffinland5671]

If the sequence was written like this: -8,32,-128,512 would the N be 512?

[@jacksherman1293]

yes

[@beto31890]

Yes

[@rebelgoldfish8727]

almost died trying to figure this out. Thanks for the help!

[@SDfighter1]

What would you do if n starts at 0?

This is great! Thanks!

[@andyfog7444]

Will the denominator always be a1 or was that just a coincidence?

[@amaababiii635]

Hello! I would like to ask how did he get 1365/32. That confuses me a bit. Thank you in advance!

[@danielyue7221]

Use the formula

[@besosalah7730]

is K same for n? because in my book they wrote K in the sigma notation instead of n but it is n in the formula of Sn !!

[@brianmclogan]

yes, any variable will work but k and n are most often used

[@besosalah7730]

thank you, sir, but may I ask another question we joust said that n is K but I faced a problem because they, in the book, found the a1 then take the end of the sum and superraces the K from it and add 1 to the answer to found n !! I'm really confused So I apologize if I bothered you with my questions

[@alexmcn7027]

you rlly boutta save my math grade huh

[@RanBlakePiano]

So fine !

[@kesavsai6641]

what if the equation next to sigma isn't in the form of a*r^n-1

[@MakaylaELove]

I understand this a little better

[@brianmclogan]

awesome! happy to help you out Makayla

[@nl6942]

What should we do if we are not given the nth term? The term on top of the sigma

[@brianmclogan]

then n will be infinity, there is a different formula for those

[@danielguastavino6634]

Nelson Lopez you wouldn't be asked that on this type of format

[@skilleryofgods8349]

Using this for finals studying!!!

[@drinkingherbalteas6792]

goodluck

[@domanicmarcus2176]

I am just curious. Why do you like to work with BIG NUMBERS? What I mean is that at the beginning instead of multiplying and dealing with BIG NUMBERS you could have reduced.4095/4096 divided by 3/4 is the same as 4095/4096 multiplied by the reciprocal of the denominator (which is 4/3). 3 is a factor of 4095. That means 4095 would divide by 3 and it would have been 1365/4096 multiplied by 4. 4 is also a factor of 4096. The final reduced fraction would have been 1365/1024 multiplied by 32. 32 is also a factor of 1024; therefore the final answer is 1365/32. If you had reduced your fractions at the beginning, you would have never needed to deal with CRAZY BIG NUMBERS; either way, GREAT JOB.

[@KatyaShazam]

what if n = 0?

[@brianmclogan]

then we would have to end at 5 and the power would be n not n-1

[@nirmalkumar1297]

Katya K u r mad.u did nt undrstnd

[@user-mk4jq7uq9c]

Thx mate

[@brianmclogan]

cheers!

[@kelemutadese964]

men you're the best

[@angelDanJonathan]

Even the master makes mistakes...

[@brianmclogan]

yes yes

[@God_3712]

I'm confused on how to get the top part of the sigma notation...

[@brianmclogan]

6? that is just how many terms you are going to add

[@onlydubya9060]

What if the number above the sigma sign, which is 6 in this case, is the letter "n", and the "n" in the problem that is an exponent to 1/4, that you did on the board, is a different letter like "m" or "i"?

[@brianmclogan]

yes then you will have an infinite series, so you will need to determine if the series converges or diverges

[@jackyreacherr5676]

This doesn’t make any sense to me, I don’t even know which numbers go where

[@bilalmansour32]

How to find R ?

[@josephschiefer8011]

You look like the bad guy from merry Christmas drake and josh

[@keshavashok2374]

Am I the only one here doing this math in 6 th grade

[@Willwrz]

I'm here in pre kindergarten 3

[@z3inab]

@@Willwrz i was just born

[@cesarh6513]

Where's mario?

[@MukeshGupta-sv5wf]

Americans are slow at calculation ?

[@piguy3144]

It’s called being a teacher. So shut the fuck up. Your name sounds like something I would say as I puke.

[@randonaneo8526]

Look at that dirty ass board

[@brianmclogan]

yeaaaaaaa

[@Creepiify]

Fail haha

[@brianmclogan]

yeah.....