Tuesday, May 12, 2009

WOF Portfolio

How is it going? What questions do you have about it? Any thoughts?

Here is a site that explains how to graph piecewise functions on the TI calculator.

Say my equations is
Y1 = -(X-2)^2 + 4

If you graph that equation, then you will see that the function has negative values when x <= 0 and when x>= 4. If you only wanted the positive values, you can enter that into the calculator by typing:
Y2 = (Y1)(X>=0)(X<=4)

NOTE: Type all of the parentheses. Use VARS -> Y_VARS -> Functions -> Y1 to enter Y1 and 2ND -> MATH -> 4 to enter >=.

Some other cool things with the calculator...type:
Y3 = Y2(X-2)
Note the placement of the parentheses. What happens? This is like doing f(x-2) or shifting the function 2 spaces to the right. Look at the table to verify this.

You could also combine functions...type:
Y4 = Y2 + Y3
What happened? Look at the table to verify this.


Anonymous said...

...How did people even start?? I can't seem to get started.

Mr. Marti said...

Can you create a table of values with time and concentration if Bob took a dose every 5 hours? What if Bob took a dose every 2 hours? Add another comment with your results.

Venus said...

how did you type in the constraints into the graphing calculator so that the equation only shows from when x is between 0-5?

Anonymous said...

IF the drug was to be prescribed at half hour intervals, would time (hours) be intervals of .5? Or is the time just measuring after 1 hour since medication ..since 2 hours ..even if the drug is prescribed at half an hour and not whole hours.

Mr. Marti said...

Venus and anyone else interested,

Here is how you can get the calculator to only graph certain regions that you are interested in:

Say your equation is:
Y1 = -(X-2)^2 + 4To only display from x = 0 to x = 4, you can then set:
Y2 = (Y1)(X >= 0)(X <= 4)Make sure you have all of the parenthesis.

NOTE: Use VARS -> Y-VARS -> Function -> Y1 to select Y1 and use 2ND -> MATH -> 4 to select >= and use 2ND -> MATH -> 6 to select <=.

Be sure to turn off Y1 or else you wont be able to see Y2. Also look at the table of values for Y2.

Mr. Marti said...

If you prescribed the drug at half hour intervals, for instance you take pill one at time 0.5 hours instead of time 0, then at time 1.5 your concentration from pill one would be 160, and at time 2.5 your concentration from pill one would be 180, etc.

Anonymous said...

how do you do number 7 on the wof unit test?