You are not logged in.

 Discussion: All Topics Topic: How to disconnect a piecewise graph

 Post a new topic to the General Discussion in PreCalculus on TI Calculator discussion
 << see all messages in this topic < previous message | next message >

 Subject: RE: How to disconnect a piecewise graph Author: MGB Date: Feb 3 2007
On Jan 30 2007, Betty14 wrote:
> If given a piecewise function, f(x)={x^2 for x<0; 2 for 0<=x<=2;
x-1
> for x>2. How should I format the graph calculator (TI-83/83+/84+) in
> order to obtain a disconnected graph instead of getting a connecting
> graph throughout the domain of the function?

Hello, you can trick your calculator into doing the piecewise function by doing
the following:

y1=(x^2)/(x<0)
y2=(2)/((x>=0)and(x<=2))
y3=(x-1)/(x>2)

note: You can get the inequality symbols from the  2nd TEST menu (on the MATH)
button and the "and"  from the TEST and then LOGIC.

How does it work? The 83/84 thinks of a true statement as a 1 and false as 0.
When the calculator is trying to graph y1, numbers less than 0 are true so the
calculator divides by 1 and gets displayed, for numbers greater than 0 it
divides by 0 and doesn't graph values that are undefined.

Look at the TABLE to see what is going on.
Good Luck.