Mathematica 2014

30

Where’s the policeman? By Mr Ottewill

2 2

2

2

y x yx + = is said to represent a policeman on traffic duty. The

The curve

graph looks like the following which illustrates the road junction.

y

4

2

-4

-2

0

2

4

x

-2

-4

The question is: where is the policeman? See below for the answer.

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Answer to ‘Where’s the policeman?’

2 2 2 y x yx + = is also true when x = 0 and y = 0, so the point (0, 0) is on the 2

graph as an isolated point – this point represents the policeman.

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