The man is an excellent teacher, the change in his voice's pitch is alone to keep the class awake and engaged. You're a rare breed Professor.
@tensaijuusan46534 жыл бұрын
I am 64 years old and I wish you had been by mathematics teacher. A good explanation and understanding of how a formula is derived rather than just a dry presentation of its mechanism can really turn on a light bulb for so many students.
@buzz_is_here3 жыл бұрын
Dude, I'm a software developer, went through (admittedly only) one year of CS UNI and this is still the best lesson on GS I've seen yet. Thank you!
@esthero1142 жыл бұрын
What is really amazing about Eddie's classes is that he gives his students the chance to experiment with different ways of trying to solve the problem instead of just giving them the answer. That way they understand why the wrong method didn't work and why the right one did.
@eshabaweja2 жыл бұрын
Watched this back in 2017 for school, watching it again in college while solving recursion trees :)
@craighennessy31832 жыл бұрын
I wish I had teachers at school with a tenth of your passion for teaching, i would have been a much better student. Brilliant stuff keep it up Eddie!
@JulianGonzalez-ej2fi Жыл бұрын
This lecture is important compared to most of the other ones because I came across this video about after 6 videos, that did not care to explain why we subtract Sn and rSn. Thank you for explaining that.
@rach83604 жыл бұрын
saving my maths a level grade one video at a time thank you!
@qtkd18194 жыл бұрын
ive been looking how to get that simple formula from SUM. Thank you so much!!
@microhoarray4 жыл бұрын
Oh my goddd this is brilliant. They always forced us to memorized
@arcadegamingpro80104 жыл бұрын
Wow great explanation sir really from now you are only my new online Math teacher ☺☺😊 thanks alot watching from INDIA.
@thehungryinvestor Жыл бұрын
Absolutly lovely way of explaining, may you make more and more videos explaining things so easily and in a fun way. These kind of teachers actually add value in the life of students, thanks for being a teacher like you are :) :).
@crisgwyngieponferrada20392 жыл бұрын
I'm a teacher. And I get ideas from you. Thank you.
@Someone-zx7xd2 жыл бұрын
I really feel like I am stupid. Why was I not able to figure out this simple proof even after thinking for many days?
@ProofDetectives11 ай бұрын
Thank you for your explanation. Have a good day.
@avanthikakatari9605 жыл бұрын
thank you for your explanation
@thebadagnostic4 жыл бұрын
Amazing explanation!
@commenter47993 жыл бұрын
I waited 14 years to go to college, and these videos really help me. I have a book, but it couldn't be a bigger piece of crap even if the pages were made of crap and those were printed on with ink made of crap. Even if they used glue made of crap to bind the book, covered it in packaging made of crap, and put it in a box made of cardboard, it still couldn't be a bigger piece of crap. With how many steps they skip in the examples and explanations, a professor would dock points if he were grading it, yet we're supposed to follow along trying to learn new concepts. In summary, I am quite dissatisfied with my calculus textbook.
@noodletropic3 жыл бұрын
Your statement rings true while humorous. Hope it get better for you.
@innochilondola8422 Жыл бұрын
Well articulated
@Pravinsahu-qf9bb7 ай бұрын
No words. Only emotion😢
@Bill-xn9tp6 ай бұрын
Beautiful.
@hhtan13466 жыл бұрын
What is the meaning "the whole things will collapse when multiply by r?" And why minus r(Sn) by Sn will get the sum of it? It's seem like counter intuitive because how the first person that create this formula will know that multiply by r and subtract them will get the answer?
@divyoroy90564 жыл бұрын
As he said, as multiplication occurs in a geometric profession, we need to cancel it with multiplication. Just like we did it for arithmetic progressions, except it is addition. Then we subtract them to cancel the terms except for a and ar^n.
@sashalo11944 жыл бұрын
HH Tan I too was wondering how the “first person to solve this” would have come to the answer. What is important to realize is that the formula for the sum is already given to you, as a plus ar plus ar^2 ... but as you can see it is long and cumbersome making it difficult to solve for efficiently. Therefore it makes sense to try to “cancel out” as many terms as possible while still being able to solve for Sn. What this derivation does is pairs all of the middle terms in two equations to cancel while still being left with Sn(1-r) on the left, allowing to solve for the sum without having tons of terms to add, creating a generalized form that only depends on the three things that define the series: first term, common ratio, and number of terms.
@divyoroy90564 жыл бұрын
@@sashalo1194 yep you're right
@morpheus61044 жыл бұрын
@@sashalo1194 Yeah, I saw it as r effectively shrinking the Series Sn from the first and last term.
@ljdowle5431 Жыл бұрын
SO GOOD!!!
@jaym65526 жыл бұрын
Sir, I thought we add terms when doing the process of elimination. Why are both positive terms in the sequence, ar and etc., canceling each other out? I am still slightly confused on this. I sincerely give my thanks for these videos. We are just given formulas to memorize and often not taught why and how they work. I understand that when my school days are over I may not remember the formulas. These videos truly help with that.
@parthrajagopalan53026 жыл бұрын
They cancel each other out as we are subtracting the second sequence FROM the first sequence (or vice versa). When we do that each corresponding term that is equal will cancel out and we'll be left with only 'a' and 'ar^n.
@dsp67426 жыл бұрын
Exactly. The Indian Education System is focused on what and not why or how.
@hellryderplayz18545 жыл бұрын
@@parthrajagopalan5302 yeah, but WHY do we do that, how does the Sn-Sn(r) function help us find the sum of the series?
@danyaaaa314 жыл бұрын
@@hellryderplayz1854 I guess we simply tried and realized that after elimination of terms we get a formula for Sn.
@hndjijwhvuwohhhrmnd2 жыл бұрын
amazing, thank you
@uniquemathematicsclassesdo27612 жыл бұрын
Please define one example where use GP concept in my daily life , I have an interest about this topic Thanks
@SamyakAditya9 ай бұрын
Thx for amazing explanation
@maxwellsequation48874 жыл бұрын
Me who tried deriving it with summation function and did in an hour, seeing him do it in some minutes : 😧😧
@maxwellsequation48874 жыл бұрын
@@amaldev3462 yes it's way more dumb Simple summing up and trying to derive stuff
@pianoforte17xx483 жыл бұрын
Well he planned for it. Proving is not on glance
@TechnoSan093 жыл бұрын
But u tried and even finished😉
@zizo-ve8ib3 жыл бұрын
I love your videos so much for real I'm a fan I have a question though, what happens if I do it using calculus, because I tried it and got the sum = a(r^n -1)/ln(r)
@ruxuesim30433 жыл бұрын
Thank you so much!
@mrhoho8 ай бұрын
thanks for sharing
@bidhancreationsudeshaschoo9924 Жыл бұрын
The sum of the 5 terms of a geometric series is 93 and the sum of the first 8 terms is 765.Then answer the following questions.Find the common ratio and first term.plz solve it.
@adleytahsin10833 жыл бұрын
Helped a lot
@fazepug19823 жыл бұрын
why was the last term (n-1) and not (n)? wouldn't (n-1) be the second last term?
@alphonseraynaud9763 жыл бұрын
there's a literally a student who asks the same question and he spends almost a minute answering it
@JannahMa Жыл бұрын
Finally i understand this
@Obase-Aboli Жыл бұрын
A capital increase in value four times one in t years, if the rate of interest is given to be 8% p.a. Determine the value of t
@jashwamesfin1392Ай бұрын
what grade do you teach
@chetnapandey1933 жыл бұрын
awesome
@khaldoonmohammed60256 жыл бұрын
شكرا جزيلا thank you
@samb96453 жыл бұрын
Hell yes!! I get it!!!
@ShehabElshehabi3 жыл бұрын
How can I proof an = an r^n-1 🧐
@You-bb5wo3 жыл бұрын
an=a1r^n-1 if you mean that then watch this video kzbin.info/www/bejne/kGfNqYuimdqHiLc
@djmelo62474 жыл бұрын
what if r=1?
@danyaaaa314 жыл бұрын
This formula was derived for r not equal to 1, as we divided by (r-1) when solving for Sn. But we can see that any "geometric progression" as r = 1 is in form a, a, a, a,..., a,.... So the sum of first n terms is just a*n. But we actually don't usually call this type of progression a geometric ptogression.
@djmelo62474 жыл бұрын
@@danyaaaa31 thanks for the anwser, understood
@danyaaaa314 жыл бұрын
@@djmelo6247 edited my answer
@asiansocrates3 жыл бұрын
Singaporeans are smart
@RamKumar-sw3yn4 жыл бұрын
I have seen that one. Do u have another one?
@25kirtan4 жыл бұрын
♥️
@daydreamer053 жыл бұрын
Your channel should be subscribed by me.
@jacobhouston16554 жыл бұрын
This wasn’t helpful. I didn’t understand why r is raised to the negative power at the end of the series. Not a good introduction.
@pianoforte17xx483 жыл бұрын
Lol he just explained it to a student.. the -1 indicates that the number of terms should be n, and the 1st term is simply r⁰ so the n-th term should be rⁿ-¹ because you count the terms as "1,2,3,...,n" not as "0,1,2,...,n" because there's no such thing as 0-th term
@alphonseraynaud9763 жыл бұрын
this must be one if the worst comments I ever read. He explains it perfectly well, answering every students' questions (including the one you ask). Please just listen to the video instead of writing such a negative comment which not only makes the video look bad although it definitely isn't but also just makes you seem dumb. Thanks