Friday 15 March 2013

Test 2

The first question on the test was great, the second was fairly great and the third was the toughest, but it was also fine. The fact that I would always get marks for structure cheered me up a lot. Here is how I did the last question.

Assume x is a real number
    Then 0 > -1
    Then  |x|  > |x|- 1                                                # |x| means floor of x
    Then  |x| > x -1                                                  # x - 1 >= |x|  - 1 by definition and by transitivity of >
    Then  |x| + 7 > x + 6
Then 'For all x in Reals', |x| + 7 > x + 6            

I had nicer structure on the test and more comments but it was the actual proof that I found challenging. Transitivity of an inequality is confusing. Either way the test went well = D.

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