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Try to answer the following questions here:

  • What is this question used for?
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Checkpoint description

Describe what's changed since the last checkpoint.

Elliott Fletcher 2 years, 3 months ago

Published this.
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Christian Lawson-Perfect 2 years, 4 months ago

Gave some feedback: Ready to use

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Christian Lawson-Perfect 2 years, 4 months ago

Saved a checkpoint:

Looks good!

Restore this checkpoint

Hannah Aldous 2 years, 4 months ago

Gave some feedback: Needs to be tested

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Christian Lawson-Perfect 2 years, 4 months ago

Gave some feedback: Has some problems

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Christian Lawson-Perfect 2 years, 4 months ago

Saved a checkpoint:

The marking is set up wrong: $k(-6)$ is the application of the function $k$, not $-6 \times k$. You can avoid this by writing $(\ldots)k$ instead of $k(\ldots)$.

It's not obvious what order you should enter the roots. The best I can come up with for a hint is "Assuming $k$ is positive, enter the lowest root first." I can't think how to be any clearer without giving a hint about the form of the answer.

You need \left and \right around brackets to make sure they stretch to fit around fractions.

Put the quadratic formula in the advice just before you list the values for $a$, $b$ and $c$.

Restore this checkpoint

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Chris Graham 2 years, 4 months ago

Gave some feedback: Has some problems

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Chris Graham 2 years, 4 months ago

When the variable C_2 is zero, your advice states $c = 0k^2$, which caused me great confusion (about where the $k^2$ had come from) when I was unlucky enough to generate this on my first attempt. If you would like to keep this scenario, then you will need to adjust the advice, or if it is not desirable then use an except in the generation of B_2 or n2. 

Hannah Aldous 2 years, 4 months ago

Gave some feedback: Needs to be tested

Vicky Hall 2 years, 4 months ago

Gave some feedback: Has some problems

Vicky Hall 2 years, 4 months ago

This is a well conceived question but the answers look a bit nasty! It would be a much nicer question if, when we get to the point of having $\sqrt(xk^2)$, the $x$ is a square number. That way we end up with some quantity of $k$ divided by $2$, which may or may not simplify, but it looks a lot better than having a surd or a decimal. 

Hannah Aldous 2 years, 4 months ago

Gave some feedback: Needs to be tested

Name Status Author Last Modified
Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ Ready to use Hannah Aldous 01/08/2017 14:06
Use the quadratic formula to solve an equation in terms of an unknown variable Ready to use Hannah Aldous 01/08/2017 13:56
Katherine's copy of Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ draft Katherine Tomlinson 02/08/2017 12:45
Emma's copy of Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ draft Emma Cliffe 31/08/2017 12:59
Peter's copy of Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ draft Peter Knowles 12/09/2017 12:39
Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ [L4 Randomised] Needs to be tested Matthew James Sykes 25/07/2018 11:06
Simon's copy of Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ draft Simon Thomas 07/03/2019 09:55
Simon's copy of Use the quadratic formula to solve an equation in terms of an unknown variable draft Simon Thomas 07/03/2019 10:00
Use the quadratic formula to solve an equation in terms of an unknown variable draft Xiaodan Leng 11/07/2019 01:50
Solve Equations of the Form $ax^2 +bx+c=0$ draft Thomas Waters 11/09/2019 22:18
Michael's copy of Solve Equations of the Form $ax^2 +bx+c=0$ draft Michael Proudman 09/10/2019 08:25
Blathnaid's copy of Use the quadratic formula to solve an equation in terms of an unknown variable draft Blathnaid Sheridan 21/10/2019 12:19
Blathnaid's copy of Use the quadratic formula to solve an equation in terms of an unknown variable draft Blathnaid Sheridan 21/10/2019 12:33

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This question is used in the following exams: