Wednesday, January 7, 2015

SBAC Calculators

Basic Calculator
This is the calculator that is embedded into the practice problems released by SBAC.  Students can work through the tutorial to learn how to enter fractions, exponents, etc.

Graphing and Regression Calculator
Here you will find the calculator that is embedded more so into the performance tasks.

There will be opportunities to learn more about these calculators soon, as well as class activities.

Tuesday, January 6, 2015

LAHS Geogebra Training 1-6-2015

Please sign in, then fill out this quick form to help us guide our time together.

Vision: Teachers and students will be proficient at using Geogebra to demonstrate thinking and to solve problems.

Goals:
-Learn about support available for integrating Geogebra into your class
-Learn how to locate and use pre-made Geogebra presentations
-Learn some basics for using Geogebra

Basics Tutorial
Screencasts
Functions
Geogebra Tools Page

Monday, January 5, 2015

Piecewise Functions for Trig/Math Analysis

We are about to start functions and transformations in trig/math analysis, so I made some piecewise functions in Desmos to use for the intro.



The above function is named f(x).  Below is what I entered to graph the function.  


Then we can view transformations of f by typing the transformation on an input line to the left of the graph.



You can show or hide each graph by clicking on the colored circle to the left of the equation.  Below is 2f(x).



And f(2x).


Here are the links to the Desmos graphs.  Graphs 3 and 4 include questions for students to answer.   Hope some of you can use them!

All of these functions were taken from Calculus AB free response questions, hence the link back to the website.  I also made a table of values to use for by-hand practice.


Watch this video by Meg Craig for a fantastic demo of how to use the table above.  Scroll down to the embedded video to view.



Friday, November 21, 2014

Square Root and Cube Root Graphing: Alg2 Section 6-5

Yep, it's that time again.  We are back to graphing, and we are back to transformations.  The book that we use for Algebra II starts in Chapter 2 with transformations of the absolute value function. Chapter 4 includes quadratics, Chapter 5 is cubics, and now in chapter 6 it is square root and cube root functions.  

Since I won't be able to help out in all of the classes this time around, I am hoping this blogpost can be helpful in getting ready for the lesson (which I taught in Jennifer C's class).  

I began the lesson by looking back at the Desmos pre-made sheet for parabolas in vertex form for a reminder of how a, h, and k transform a graph.

 I decided to take a different approach for the intro to 6-5.  Instead of starting with functions and table of values, I started with a transformation given in words.



I showed the Geogebra applet below.  Directions are to move points A, B, and C so they are first ON the square root graph, then shift each point up from the parent graph by two.  Students could pick which of the points from the parent graph to look at, as long as A, B, and C are two units up from a point on the parent graph of y=sqrt(x).

 Step 1:

Step 2:


Next I typed the y=a*sqrt(x-h)+k into the input bar, and we talked through the transformations that had taken place.  I changed a, h, and k as we decided on values.  For this example a=1, h=0 and k=2.




If you have entered the correct function into the input bar (hit enter when finished), the transformed function will turn green if correct.



Students practiced a few problems with both horizontal and vertical translations, and then problem 5 asked students to reflect y=sqrt(x) about the x-axis.  About 90% of students were able to move points A, B, and C to the correct location, and about 50% correctly guessed that the correct transformed function was y=-sqrt(x).  This was with NO direct instruction for this part of the lesson.  I was hoping for this moment, as one of my goals for this approach was for students to think about how we were transforming a set of points, and specifically to think about what happens to a set of points before we think about the transformed function.  I did call the class back together to finish up problem 5.  I also walked them through problem 14 so that they would get a chance to see a cube root transformation modeled by teacher.

You can access the problem set here, as well as from the email attachment.  There is space to record transformed points and the transformed function.  Answers can be checked using the applet, which is set up to indicate a correct answer as long as your transformed function went through points A, B, and C.  Since students were checking their own answers, I got to walk around and asked questions to check for understanding.  No doubt it is too many problems, and would have been much better on a block day, but it still was a great experience for students.  Overall, I like this approach for introduction to graphing a new type of function in Algebra II, and I can see adapting this lesson for the other function types (with tweeks of course!).

One last note is that it is possible for students to get the wrong "answer" using this applet.  The floating points A, B, and C begin at (1,4), (4,4) and (7,4), so if a student enters the function f(x)=4 the applet will indicate that they are correct.  This has happened a few times since I started using applets like this one, and it's made for great conversation and reinforces the need to check the reasonableness of an answer.  


Thursday, October 30, 2014

I Spy II: Class Activity

This post gives a few samples from the follow up activity for the I Spy introduction to congruent triangles activity.  The directions that will be given to students are:

I Spy
Directions: Each diagram has a pair of triangles.  One triangle has been either translated, reflected, or rotated to create the second triangle.  As you view each diagram, see how many of the following objects you can find.

-Angle Bisector
-Midpoint
-Isosceles Triangle
-Parallel Lines (or parallel segments)
-Right Angles


Team Directions:  Each team member should use a different color marker to record responses to the problems.  Switch roles for each problem.

There are 6 problems to total to give the groups.  The first two are easier than those shown below, with only one conclusion (I spy item) to make from the diagram.  The photos below are provided as a preview for this activity.  The full problem set with directions is available here.






I Spy: Introduction to Congruent Triangles

Below is an introduction to congruent triangles that makes use of student prior knowledge of transformations.  It also encourages students to deduce information from a diagram and to justify their reasoning. 

Show students the following diagram, and go through the steps below.  Some questions/prompts are shown in blue.


1.  What type of transformation is shown in this diagram?

2.  Reveal the measures of ABC.  Ask students, “Who thinks they know another measure in the diagram?  Be ready to explain your answer.  Show me ONE other measure that you know, and hold up your whiteboard when you are ready.”  Teacher can show answers from students that used notation correctly.  Reveal the measures of AFE.



3. Show students the statement below.


Ask them how we might fill in the blank, and why.


4.  Move point C to the horizontal line (you can do this in the Geogebra applet).  


Leaving the measurements showing, ask students to tell you what they “spy”.  They can write on their whiteboards, “I spy __________________.”  Answers must be defended.  Make sure to have the list of possible answers written on the whiteboard.  

The choices are angle bisector, midpoint, isosceles triangle, parallel lines, and right angles.

3.  Move point B to F. Move point A down the vertical line so your diagram looks like the one below.




Leaving the measurements showing, ask student to tell you what they “spy”.  They can write on their whiteboards, “I spy __________________.”  Answers must be defended.

I SPY CHOICES:  angle bisector, midpoint, isosceles triangle, parallel lines, and right angles.

4.  Turn the measurements off.  Move point A back up to the horizontal line, and make sure point B is on point F.  Ask student to tell you what they “spy”.  They can write on their whiteboards, “I spy __________________.”  Answers must be defended.



I SPY CHOICES:  angle bisector, midpoint, isosceles triangle, parallel lines, and right angles.

Extension if there is time:  Since we haven’t seen parallel lines yet in this dynamic diagram, ask students how we can modify the diagram to form parallel lines (and explain why).

There is a second page in the Geogebra Book that has a triangle rotated around a vertex by 180 degrees to form the second triangle.  

Part II will have the I Spy Class Activity if you have time for it.