history of mathematics - National STEM Centre
history of mathematics - National STEM Centre
history of mathematics - National STEM Centre
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outcome<br />
1 step to the right<br />
Figure 13.1<br />
162<br />
13 Hints<br />
1 step<br />
upwards'<br />
To stage the debate, or to draw up a plan for your presentation or essay, you could<br />
consider the following format:<br />
• first, summarise Arnauld's extract in Activity 10.10;<br />
• secondly, summarise Euler's and Saunderson's extracts.<br />
In each case you should draw out the key points. Then, you could start on the<br />
debate by<br />
• presenting what Arnauld is likely to believe is the flaw in Euler's and<br />
Saunderson's arguments;<br />
• allowing Euler and Saunderson to answer back or counterattack.<br />
Remember not to use modern arguments to present the flaws in the various<br />
arguments. Try to argue from the points <strong>of</strong> view <strong>of</strong> Arnauld, Euler and Saunderson<br />
based on what you know <strong>of</strong> them from the extracts. You could consult your list <strong>of</strong><br />
assumptions made by Euler and Saunderson; by looking at them can you find a<br />
'chink in their armour' from Arnauld's point <strong>of</strong> view, or vice versa?<br />
Activity 77.7, page 138<br />
1 How did you set about establishing the result for the product <strong>of</strong> two negative<br />
numbers? You should consider whether the process you used was a justifiable one<br />
given the original role <strong>of</strong> the numbers a, b, c and d.<br />
Activity 11.4, page 141<br />
1 One counter-example is the answer given to question Ic in Activity 10.10 in<br />
connection with Arnauld's opposition to negative numbers.<br />
Activity 11.8, page 143<br />
1 b The operations for combining the elements in Boole's algebra will not be<br />
labelled by + and x and the elements will not be labelled by numbers. Imagine<br />
replacing the symbols in the rules for combining Boole's elements by + and x in a<br />
suitable way and imagine the elements to be numbers. Would the rules then look the<br />
same as those for the number system? If not, how would they differ?<br />
Activity 11.10, page 145<br />
1 To get started, here is part b as an example; you can then try the other parts.<br />
Take a step <strong>of</strong> one unit to the right (i) and add to it a step <strong>of</strong> one unit 'upwards', (j).<br />
This produces a step as shown in Figure 13.1 but not in either <strong>of</strong> the basic directions<br />
(to the right and upwards); it is inclined at an angle to the basic directions.<br />
What is the angle at which this new step is inclined and what is its length?<br />
Activity 11.12, page 146<br />
2 b Think about something you take for granted with real numbers. When you<br />
multiply three numbers together can you multiply them in any order; does the order<br />
matter?