A-Level Maths: D3-02 Sigma Notation: Writing a Series in Sigma Notation

[@rosettegolda232]

People have always recommended your videos and I've disregarded them for whatever reason. But watching this has made SO MUCH SENSE! I wish I'd been watching your videos since the start of year 12!

[@humanloll]

You're absolutely GOD SENT. Thanks a million for these videos!

[@Kaif]

TL the 🐐

[@reekova7832]

You've made it understandable for me.

[@paulstanton4604]

Thanks, really helpful video.

[@enosrusike9574]

Thank you now I understand these things they are so easy

[@z_6077]

Hey, I was just wondering for the nth term of questions 3 and 4, do I have to write my answer in the form that you have given it or can I write the way I want, because another way to write the nth term for question 3 (for example) is Un= (-4/21)n+11/21

[@TLMaths]

You CAN write the nth terms in different ways, yes. I'm not sure where you're getting (-4/21)n+11/21 from for (I think you meant question 4) as it produces the sequences 1/3, 1/7, -1/21, -5/21, -3/7 ?

[@abdirahmanahmed6808]

Do you need to know example 3,4,5 type sequences for edexcel alevel? I thought it was only geometric or arithmetic

[@TLMaths]

They are the two types of sequences you'll have to deal with for summing series problems, true, but you should still be able to find nth terms for sequences like these