,
=, and 
from
the TEST menu are evaluated by the calculator as either 1 or 0 according
as the expression is true or false for a given value of x. Thus, (x>2)*(3x–1)
evaluates to 0*(3x–1)=0 when x£2
and to 1*(3x–1)= 3x–1 when x>2.General method: The trick to this is knowing that expressions involving,
<, >, £,,
=, and from
the TEST menu are evaluated by the calculator as either 1 or 0 according
as the expression is true or false for a given value of x. Thus, (x>2)*(3x–1)
evaluates to 0*(3x–1)=0 when x£2
and to 1*(3x–1)= 3x–1 when x>2.
Example: To graph the function,
insert the following formula as Y1
Y1= (X<1)(X+1)+(X=1)(3)+(X>1)(1–X)
Notes:The inequality and equality symbols are found in the TEST menu.
Isolated points such as (1, 3) in the above example will not be visible unless you insure that the x-coordinate of that point is used by the calculator as a plotted point. Usually, this can be handled from the ZOOM menu by selecting ZDecimal.
Also, if the "connected" option is turned on for this type of graphing, you will get false information at discontinuities. To turn this off, choose MODE and select the DOT setting rather than the CONNECTED setting for plotting.
| Here is what the above function should look like if graphed as described above. | ||||
 |
