## Sunday, March 13, 2016

### Day 119: Definition of a Function & Graphing Form to Determine # of solutions

The estimation was how many marshmallows will fit on a skewer. I liked when students mentioned the light reflections as landmarks for how to estimate.

I gave students the definition of a function as well as the definition of a vertical line test. I used the same notes as last year, under "We out here trying to function" from last year. Basically I give students a non-example, x=y^2, we analyze the table first, then the graph. Then they analyze y=x^2 and see that it's okay to have 2 of the same output for 2 different inputs. It is not OK, on the other hand, for two different inputs to have the same output.

In accelerated students determined how many solutions there were to a quadratic equation by completing the square and putting it in graphing form. If 0 was on the right side, the square root of 0 is 0, so it has only one solution or x-intercept. That was an interesting interpretation students had to make. Also, if you get the square root of a negative number then you have no real solutions. Finally, there's 2 solutions if you can plus or minute a positive square root.

Then students took an assessment. I'm planning a busy pi day on Monday with a brainstorm, in partners measuring a circle's circumference and diameter, getting the line of best fit, and finally seeing that the slope is 3, or 3.14 or pi. A circumference of any circle is always 3.14 times the length of the diameter, because circumference divided by diameter is a special ratio called pi. Here is the google form link I want to give out to student partnerships to collect data.

Procedure:

1. Measure the circumference of your circle by putting the string around the edge, and then straightening it out on a meter stick.
2. Then measure the diameter from 1 edge of the circle through the center to the other side.
3. Go to this link to submit your data: