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### History and Feedback

#### Checkpoint description

Describe what's changed since the last checkpoint.

#### lucia ramsey2 months, 1 week ago

Gave some feedback: Ready to use

#### Christian Lawson-Perfect1 year, 8 months ago

Gave some feedback: Ready to use

#### Christian Lawson-Perfect1 year, 8 months ago

Saved a checkpoint:

Looks like there was an off-by-one error.

#### Deirdre Casey1 year, 8 months ago

In part b does not accept correct answer. Mistake also shown in the solutions.

#### Deirdre Casey1 year, 8 months ago

Gave some feedback: Has some problems

#### Christian Lawson-Perfect1 year, 12 months ago

Gave some feedback: Ready to use

#### Christian Lawson-Perfect1 year, 12 months ago

Saved a checkpoint:

Gave the variables sensible names and reworded some of the advice.

#### Elliott Fletcher1 year, 12 months ago

Published this.

Gave some feedback: Needs to be tested

Splitting into 3 questions with 3 parts each instead of 3 parts with 3 gaps

#### Christian Lawson-Perfect2 years ago

And like the other sequences questions, the advice would benefit hugely from a table.

#### Christian Lawson-Perfect2 years ago

Gave some feedback: Has some problems

#### Christian Lawson-Perfect2 years ago

Saved a checkpoint:

The gaps are all set as "mathematical expression", but there's no reason they shouldn't be "number entry" (apart from the formula part, obv.)

The parts of this question aren't coherent; you could keep the same sequence throughout, and ask the student to:

• Find the common ratio
• Give the formula for the $n$th term
• Calculate a given term.

#### Hannah Aldous2 years ago

Gave some feedback: Needs to be tested

#### Lauren Richards2 years ago

• Make sure i) and ii) etc are in italics both in the parts and the advice.
• I think I would capitalise "Common ratio" in part a).
• Advice content for a) is fine.
• Where you have stated what the formula for the geometric sequence is in part b) of the advice, I think you should explain that a is the first term and r is the common ratio.
• Make sure you use displaystyle to make the formula large.
• Think there might be a slight glitch in the advice of c) where you are trying to figure out the common ratio, it says a[3]*a[4]^3 instead of 375 as it was supposed to be in this case.
• Typo in the last sentence of the advice - it says "we can write substitute them into the formula..." - "We" should be capitalised and just scrap write.

#### Lauren Richards2 years ago

Gave some feedback: Has some problems

#### Hannah Aldous2 years ago

Gave some feedback: Needs to be tested

#### Vicky Hall2 years ago

It would also be helpful to give and exlain the formula for the $n$th term in the statement.

#### Vicky Hall2 years ago

Gave some feedback: Has some problems

#### Vicky Hall2 years ago

I have added a sentence to the statement to explain what is meant by the common ratio. I think part a) should include one sequence with a positive integer ratio, one with a negative integer ratio and one with a fractional ratio to cover all possibilities.

#### Hannah Aldous2 years ago

Gave some feedback: Needs to be tested

#### Hannah Aldous2 years ago

Created this.
Find and use the formula for a geometric sequence Ready to use Hannah Aldous 14/05/2019 14:59
Deirdre's copy of Find and use the formula for a geometric sequence draft Deirdre Casey 06/11/2017 12:40
Marte's copy of Find and use the formula for a geometric sequence draft Marte Bråtalien 12/04/2018 14:12
Joël's copy of Find and use the formula for a geometric sequence draft Joël Cohen 27/08/2018 12:35
Hallar el término general de una secuencia geométrica. Ready to use Luis Hernandez 14/01/2019 13:17
Simon's copy of Find and use the formula for a geometric sequence draft Simon Thomas 25/02/2019 10:50
Justin's copy of Find and use the formula for a geometric sequence draft Justin McGuinness 14/05/2019 15:02
Find and use the formula for a geometric sequence draft Xiaodan Leng 10/07/2019 21:48

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