Q1. How to use this pattern ?
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* Row 1 : numbers in triangular number patterns
* At row 1 and column x the number is x*(x+1)/2
* For example at row 1 column 10 the number is 55
Q2. Find the number at row r and colum c
A2. Answer
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* Number = 1 + 2 + 3 + .... (r+c-2) + c
* E.G. Number at row 1 and colum 4 is 10
* E.G. (r+c-2) = 3 Hence 1 + 2 + 3 + 4 = 10
Q3. Find row and column for number 11 ?
A3. Answer
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* At row 1 and column x greater than 11 is 15
* Hence x*(x+1)/2 <= 11
* Hence x = 4, x*(x+1)/2 = 10
* Hence x = 5, x*(x+1)/2 = 15
* Hence row number is r = (15 - 11) = 4
* Hence col number is c = x - (15-11) = 1
Reference
- See Mathematics Dictionary Program 14 17
Now you should install Mathematics Dictionary on your computer
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(1) You can see many many diagrams for your school mathematics
(2) You can use it as graphic calculator for home work