Discussion: The student works out the number of regions made with 3,4,5 and 6 lines and observes a pattern and attepts to prove it by induction. The induction is correct except that there is no explanation for why one adds n+1 though one might ascertain this from looking at the diagrams. Though on-target the student mis-states the formula for the sum of the first n integers.

Written Response; Induction is the way to go to prove this classical identity. Your argument needs to be tightened and more exposition is needed/

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