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### History

#### Checkpoint description

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Published this.

#### Christian Lawson-Perfect2 years, 12 months ago

Gave some feedback: Ready to use

#### Christian Lawson-Perfect2 years, 12 months ago

Saved a checkpoint:

Looks good!

#### Hannah Aldous3 years ago

Gave some feedback: Needs to be tested

#### Christian Lawson-Perfect3 years ago

Gave some feedback: Has some problems

#### Christian Lawson-Perfect3 years 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 $c$.

#### Chris Graham3 years ago

Gave some feedback: Has some problems

#### Chris Graham3 years 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 Aldous3 years ago

Gave some feedback: Needs to be tested

#### Vicky Hall3 years ago

Gave some feedback: Has some problems

#### Vicky Hall3 years 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 Aldous3 years ago

Gave some feedback: Needs to be tested

#### Hannah Aldous3 years ago

Created this as a copy of Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$.
Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ Ready to use Hannah Aldous 20/11/2019 14:45
Use the quadratic formula to solve an equation in terms of an unknown variable Ready to use Hannah Aldous 20/11/2019 14:44
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
06 - Knowledge Assessment Criteria 1.4.2 (Quadratics by formula) draft Michael Proudman 29/04/2020 14:48
Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ draft Patrick Delassus 05/05/2020 14:54
ALG Solución de Ecuaciones Cuadráticas $ax^2 +bx+c=0$ draft David Vanegas 05/06/2020 02:24

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This question is used in the following exams: