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### History

#### Checkpoint description

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#### Martin Kilian1 year, 4 months ago

Gave some feedback: Ready to use

#### Luis Hernandez1 year, 8 months ago

Gave some feedback: Has some problems

#### Luis Hernandez1 year, 8 months ago

Gave some feedback: Ready to use

#### Christian Lawson-Perfect3 years, 1 month ago

Saved a checkpoint:

I don't think this question is worth saving. I've split part d, about finding a given term, into a separate question.

Ideally, there'd be a question combining parts a and b, asking you to sort a few sequences into linear, quadratic, geometric, or other.

I don't think there's any point in the parts which ask you to give the next three terms of the triangle, square, and cube numbers.

#### Christian Lawson-Perfect3 years, 1 month ago

Gave some feedback: Should not be used

Published this.

#### Bradley Bush3 years, 2 months ago

Gave some feedback: Needs to be tested

#### Bradley Bush3 years, 2 months ago

Thank you for the feedback Christian:

• I have added tables to the feedback for parts and b to make the working easier to follow.
• I have added a table to the feedback for c also to analyse the difference between terms but I have included Hannahs solution using the formula as an alternative method of solving this.
• I have altered question d to be the more generic randomisable sequence equation which you suggested.
• I attempted to explain the solution using a table here to find the differences too but I am not too sure how thoroughly this would explain the way you work out that the sequence is squared numbers and cubic numbers without simply recognising them. Nor am I confident I even know how to recommend solving this problem if you do not recognise the squared or cubic terms on your own?

#### Christian Lawson-Perfect3 years, 2 months ago

Gave some feedback: Has some problems

#### Christian Lawson-Perfect3 years, 2 months ago

Saved a checkpoint:

Advice for part a could show each sequence with the common differences underneath, so it's easy to see which are linear. That's how I'd work it out.

Similarly with common ratios for part b.

For part c, I just use the fact that the difference between consecutive triangle numbers increases by 1 at each step. A drawing of the first few triangle numbers would help show this. While you can use the formula, it's not obvious, and you'd look at common differences first.

In part d, rather than using the triangle sequence in particular, I'd give a formula of the form $\frac{an(n+b)}{c}$ (what constraints are there on randomising this?) - you want to see that the student's comfortable with using a formula to get the nth term of a sequence without working out all the previous terms.

Part e relies on noticing that the sequences are the squares and cubes, respectively. How would you work this out? It's not enough to just state it in the advice. You might look at common differences, then make a guess that it's $n^2$ or $n^3$. The advice should show this experimental thinking - is it really $n^2$? How do we check? Draw a table of $n$ against $a_n$?

#### Hannah Aldous3 years, 2 months ago

Gave some feedback: Needs to be tested

#### Hannah Aldous3 years, 2 months ago

Created this as a copy of Finding the $n^{\text{th}}$ Term of a Quadratic Sequence.
Arithmetic sequences in an ice cream shop Ready to use Hannah Aldous 20/11/2019 14:36
Compute the partial sum of an arithmetic sequence Ready to use Hannah Aldous 20/11/2019 14:36
Finding the $n^{\text{th}}$ Term of a Quadratic Sequence Ready to use Hannah Aldous 20/11/2019 14:39
Identifying different types of sequences Ready to use Hannah Aldous 20/11/2019 14:40
Finding the formula for the $n^{\text{th}}$ term of linear sequences Ready to use Hannah Aldous 20/11/2019 14:39
Partial sum of an arithmetic sequence - birthday money Ready to use Hannah Aldous 20/11/2019 14:41
Find common difference in arithmetic sequences with gaps Ready to use Christian Lawson-Perfect 20/11/2019 14:39
Fill in the gaps in an arithmetic sequence Ready to use Christian Lawson-Perfect 20/11/2019 14:39
Write down and apply the formula for an arithmetic sequence. Ready to use Christian Lawson-Perfect 20/11/2019 14:46
Finding the Formula for the $n^{\text{th}}$ Term of Linear Sequences draft Chris Graham 20/07/2017 15:08
Inbbavathie's copy of Find common difference in arithmetic sequences with gaps draft Inbbavathie Ravi 24/07/2017 03:48
Find a particular term of a sequence using the given formula Ready to use Christian Lawson-Perfect 20/11/2019 14:38
Johan's copy of Write down and apply the formula for an arithmetic sequence. Has some problems Johan Maertens 02/08/2017 17:51
Finding the formula for the $n^{\text{th}}$ term of linear sequences draft steve kilgallon 19/11/2017 08:09
Compute the partial sum of an arithmetic sequence draft steve kilgallon 19/11/2017 08:11
Identifying different types of sequences draft Luis Hernandez 31/12/2018 01:38
Calcular la suma parcial de una sucesión aritmética Ready to use Luis Hernandez 14/01/2019 17:37
Identificando diferentes tipos de secuencias Ready to use Luis Hernandez 14/01/2019 13:19
Suma parcial de una secuencia aritmética - Cumpleaños Ready to use Luis Hernandez 14/01/2019 19:01
Encontrar la diferencia común en una Secuencia Aritmética Ready to use Luis Hernandez 14/01/2019 17:40
Encuentra un término particular de una secuencia usando la fórmula dada Ready to use Luis Hernandez 14/01/2019 17:48
Encontrar la fórmula para el término $n^{\text {th}}$ de una secuencia lineal Ready to use Luis Hernandez 14/01/2019 19:29
Simon's copy of Write down and apply the formula for an arithmetic sequence. draft Simon Thomas 25/02/2019 10:20
Simon's copy of Find common difference in arithmetic sequences with gaps draft Simon Thomas 25/02/2019 10:24
Simon's copy of Finding the formula for the $n^{\text{th}}$ term of linear sequences draft Simon Thomas 25/02/2019 10:30
Identifying different types of sequences draft Xiaodan Leng 10/07/2019 21:48
Write down and apply the formula for an arithmetic sequence. draft Xiaodan Leng 11/07/2019 01:48
Fill in the gaps in an arithmetic sequence draft Xiaodan Leng 11/07/2019 01:48
Find common difference in arithmetic sequences with gaps draft Xiaodan Leng 11/07/2019 01:49
Compute the partial sum of an arithmetic sequence draft Xiaodan Leng 11/07/2019 01:51
Partial sum of an arithmetic sequence - birthday money draft Xiaodan Leng 11/07/2019 01:54
Arithmetic sequences in an ice cream shop draft Xiaodan Leng 11/07/2019 01:55
Finding the formula for the $n^{\text{th}}$ term of linear sequences draft Xiaodan Leng 11/07/2019 01:55
Find a particular term of a sequence using the given formula draft Xiaodan Leng 11/07/2019 01:56
Finding the $n^{\text{th}}$ Term of a Quadratic Sequence draft Xiaodan Leng 11/07/2019 01:57
Paul's copy of Inbbavathie's copy of Find common difference in arithmetic sequences with gaps draft Paul Verheyen 17/04/2020 12:54
ibrahim's copy of Finding the formula for the $n^{\text{th}}$ term of linear sequences draft ibrahim khatib 21/12/2019 11:17
Sucesiones aritméticas draft David Vanegas 05/06/2020 02:19
Compute the partial sum of an arithmetic sequence Ready to use Vicky Hall 21/09/2020 09:34
Ashley's copy of Identifying different types of sequences draft Ashley Cusack 16/09/2020 20:54
Abrari's copy of Fill in the gaps in an arithmetic sequence Ready to use Abrari Hasmi 19/09/2020 16:58

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