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Printjmc
algebra senior
Problem
Below is a portion of the graph of a function, :

What is the sum of all integers in the interval shown () such that ?
What is the sum of all integers in the interval shown () such that ?
Solution
We could check separately for each integer from to : for example, , so , but , so , and so on.
However, it is easier to see at a glance which satisfy by superimposing a graph of on the graph of :
The six blue dots above mark the integer points which lie below the graph of , indicating that . Their -coordinates are which add up to .
However, it is easier to see at a glance which satisfy by superimposing a graph of on the graph of :
The six blue dots above mark the integer points which lie below the graph of , indicating that . Their -coordinates are which add up to .
Final answer
26