Transition to university

Chris Graham commented on Find the equation of a line through two points - positive gradient 8 years, 5 months ago

Similar points to our earlier discussion: 

This is a candidate for using the Numbas variables to set the jsxgraph axis limits. Move the block of code where you grab the Numbas variables in front of making the board, so that you have access to them. And then you can use them in the bounding box definition boundingBox:[yb-2,...] or whatever is sensible. Don't forget you'll want the intercept to be on the board.

Since you are only asking for the equation of the straight line through the points, you might consider creating a step with gapfills for the gradient and intercept, to allow the student to break the question down.

And you could add a second plot with the solution to the advice. 

One final thing: on one run I had B at the origin. You may wish to avoid this as it makes parts of the advice obsolete.

Chris Graham on Find the equation of a line through two points - positive gradient 8 years, 5 months ago

Gave some feedback: Has some problems

Chris Graham commented on Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ 8 years, 5 months ago

Nearly there!

In the steps you'll need to give the form of the quadratic equation associated with the solution, to assist the student in identifying $a$, $b$ and $c$.

Chris Graham on Using the Quadratic Formula to Solve Equations of the Form $ax^2 +bx+c=0$ 8 years, 5 months ago

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Chris Graham on Which coin is more likely to be biased? 8 years, 5 months ago

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Chris Graham commented on Which coin is more likely to be biased? 8 years, 5 months ago

I got 5 heads and 5 tails for the "distractor", which makes part a) very straightforward. I suggest that the imbalance in proportion of heads/tails is greater for coin 2 that coin 1, as it was when you put it up on the screen in the learning lab. 

I suggest the following changes to the wording:

• In the statement on the first line: "It is known that one of the coins is biased".
• Part a): "Based on the available results, ..." 

In the advice:

• "..., which would be the case for an unbiased coin". It is true in any case. The point being for an unbiased coin you would expect this to approach 0.5. You should explicitly state this. 
• "theoretical probability... should be..." it is a fact for an unbiased coin, no should about it.
• "is greater than 50%" would cover 70, 51, 50.00001. You probably don't want to get bogged down in compound probability calculations, but "signficantly different" would be an improvement. 
• Same with the "is greater than 50%" in part b).

Chris Graham on Probability - Notation and Conversion between Percentages, Decimals and Fractions 8 years, 5 months ago

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Chris Graham commented on Probability - Notation and Conversion between Percentages, Decimals and Fractions 8 years, 5 months ago

In the advice, it is not conventional that a comma is placed at the end of the line within a derivation or calculation, as you have with something like

\[\begin{align} x &= \frac{1}{10}\text{,} \\ &= 10\%\text{.} \end{align}\]

An appropriate place to have a comma at the end of a line within the align environment is where you have something more like a list:

\[\begin{align} x_1 &= 2\text{,} \\ x_2 &=4\text{.} \end{align}\]

Sorry, this is probably me brainwashing you about punctuation!

Also, your statement is unrelated to the question content, which is really about conversion. You can keep it in, but should expand on it. 

Chris Graham commented on Finding the highest common factor of two numbers 8 years, 5 months ago

I had 25 marked as prime in part b). I think you may need to update the marking matrix after removing the choice below? 

Chris Graham on Finding the highest common factor of two numbers 8 years, 5 months ago

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Bradley Bush on Match statement to graphs 8 years, 5 months ago

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Stanislav Duris commented on Working with standard index form 8 years, 5 months ago

I split this question into 4 different questions numbered 1, 2, 3 and 4.

Bradley Bush on Straight line equation application: measuring sunflower height 8 years, 5 months ago

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Stanislav Duris on Multiplication and division of numbers in standard index form 8 years, 5 months ago

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Stanislav Duris on Addition and subtraction of numbers in standard form 8 years, 5 months ago

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Stanislav Duris on Addition and subtraction of numbers in standard form 8 years, 5 months ago

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Lauren Richards on Finding the highest common factor of two numbers 8 years, 5 months ago

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Stanislav Duris on Converting from standard index form to decimal. 8 years, 5 months ago

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