Category Archives: graph transformations

Is this a graph of a quadratic function?

Here’s an idea that came to me in Anne Watson’s plenary today at the MEI conference in Keele.  I think it’s quite challenging but I haven’t used it with any classes yet, so have no idea really!

Screen Shot 2017-07-01 at 15.28.10.png

I expect students to think of translating the graphs along x and y so that the turning point ends up at the origin.  Then they can test whether y = x² .  What other methods might you use? What other prompts might you give  to learners that are stuck? What additional questions could you ask?

Here is the above image as a pdf.  I created it in Excel here as a scatter graph with a smoothed curve, so can tweak the values if you wish.