Here is the answer to the challenge problem of Lesson 2 Day 2:

The function is y = -x^2 +2.

The focus for this parabola is (0,1.75) with directrix y= 2.25:

Here is a close up showing how one arm of -x^2 + 2 passes through the minimum point:

This picture is that of the parabola at its' maximum point at (0,2):

Click HERE to see the movement of ax^2 + bx + c with respect to time. Try to identify which moving graph corresponds to the three variations of ax^2 + bx + c that was discussed. To start the movie, click on the lower left arrow; To close, click on the upper left box.

I believe for demonstration, if 5 graphs were produced then careful explanation is required to avoid any confusion. If 1 graph at a time were demonstrated, one would need an explanation for each one and then a summary of all the graphs to avoid confusion. In all cases, an explanation is essential.

 

 

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