Math 142 c Roberto Barrera, Fall 2015
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Finding Function Values:
1) Enter the function into Y
1 by pressing Y = .
2) On the home screen ( 2nd , MODE ), call Y
1 by pressing VARS , Y-VARS , FUNCTION ,and
1 . Then, open parenthesis, type the input value, and close parenthesis. You should have something like Y
1
( 2 ) . Press ENTER .
Intersect Function:
1) Press Y = and enter the left side of the equation into Y
1 and the right side into Y
(Make sure your Stat Plots 1, 2, and 3 are off –unhighlighted.)
2
.
2) Try ZOOM , 6 ; ZOOM , 0 ; or WINDOW (adjust) and then GRAPH . (Remember, you must be able to see the intersection point in your window.)
3) Press 2nd , TRACE , and 5 .
4) Move your cursor close to the intersection point, and press ENTER for the first curve, ENTER for the second curve, and then ENTER again for “Guess?”.
Zero Function
1) Enter the function into Y
1 are off –unhighlighted.) by pressing Y = . (Make sure your Stat Plots 1, 2, and 3
2) Try ZOOM , 6 ; ZOOM , 0 ; or WINDOW (adjust) and then GRAPH . (Remember, you must be able to see where the function crosses the x -axis, i.e. where the function equals 0.)
3) Press 2nd , TRACE , and 2 .
4) The calculator will prompt you for the LeftBound. Use your left or right arrow key

Math 142 c Roberto Barrera, Fall 2015
2 to move the cursor to the left of where the function crosses the x -axis and hit ENTER .
The calculator will then prompt you for the RightBound. Move the cursor to the right of where the function crosses the x -axis and hit ENTER .
5) The zero will appear at the bottom of the screen.
Graphing Piecewise Functions This will be shown by two examples.
y =
( x x ≤ 0
− x + 2 x > 0
1. Press Y= .
2. In the Y
1 line, first enter the first fucntion in parentheses: ( X ) .
3. On the same line, we need to specify that this is true for x ≤ 0. This needs to be entered in parentheses as well. Press ( to open the parentheses and then X . To find the ≤ sign, press 2 nd
MATH to get the operators. Press 6 or scroll down to
≤ and press ENTER . Then press 0 .
4. To enter in the − x + 2 part, on the same ( Y
1
) line, press + and proceed as in step
3. for the second part of the piecewise function.
Your Y
1 line for y should be Y
1
= ( X )( X ≤ 0 ) + ( − X + 2 )( X > 0 ) .
For y =
 x x ≤ − 1


1 − 1 ≤ x ≤ 1 ,


− x 1 ≤ x everything is the same as in the previous example except you have to write − 1 ≤ x ≤ 1 as − 1 ≤ X and X ≤ 1. The and is found by pressing 2 nd
LOGIC. Your Y
1 line for y should be
MATH and scroll right to
Y
1
= ( X )( X ≤ − 1 ) + ( 1 )( − 1 ≤ X and X ≤ 1 ) + ( − X )( 1 ≤ X )
Checking Values of a Function
1. Graph the function.
2. Press 2 nd
TRACE (CALC) and press 1 or scroll to “value” and press ENTER .
3. Enter the desired x value and press ENTER

Math 142 c Roberto Barrera, Fall 2015
Checking Values of a Function on a Table of Values
1. Enter the function you want the values of.
2. Press 2 nd
WINDOW (TBLSET).
3. Change “Indpnt” from “Auto” to “Ask”.
4. Press 2 nd
GRAPH (TABLE).
5. Enter in values you want to check.
Press DEL for the rows you want to delete in the table.
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