Two Sign Errors
A student checking an integral asks what to do if they catch two sign errors. Two sign errors cancel out, so you might as well not catch any.
Transcript
"And what if I catch *two* sign errors?" "Then you might as well not catch any!" [Paper: ∫ from −1 to 0 of −e^(−x) dx = e^(−x) from −1 to 0 = 1 − 1/e]
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Free for classrooms, worksheets, slides and other non-commercial use under CC BY-NC 4.0, with credit to Ben Orlin.
Cartoon by Ben Orlin, Math with Bad Drawings. https://cartoons.mathwithbaddrawings.com/2018-01-17-two-sign-errors/ (CC BY-NC 4.0)