Page 778 - Algebra 1

Math Reasoning
Verify Use a graphing
calculator to show that
_x2 - 3 is the same
2 _x2
as (2 )- 3. Explain.
Solving with a Graphing Calculator
Solve each system of equations by using a graphing calculator.
_2
a. y=x -3 2
y=x-3 SOLUTION
_2
EnterY1= x -3andY2=x-3. 2
The display shows two graphs: a parabola and a line.
Use TRACE to approximate the solutions first. Then confirm the answers using INTERSECT.
The display shows the coordinates of the two points of intersection.
The first point of intersection is (2, -1) and the second point of intersection is (0, -3).
Check
Substitute (2, -1) into both equations.
Example
2
Graphing Calculator Tip
For help with graphing systems, refer to the graphing calculator keystrokes in Graphing Calculator Lab 5 on p. 352.
_2 y=x -3 2
_2 -1 (2) -3 2
y=x-3 -1 2 - 3 -1 = -1 ✓
-1 = -1 ✓
Substitute (0, 3) into both equations.
_2 y=x -3 2
_2 -3 (0) -3 2
-3 = -3 ✓ b. y=x2
y = 2x - 2 SOLUTION
y=x-3 -3 0 - 3 -3 = -3 ✓
EnterY1=x2 andY2 =2x-2.
The display shows two graphs: a parabola
and a line.
The display shows that the parabola and the line
do not intersect, so there are no solutions to this system.
If the calculator is used to find a point of intersection, an error message is displayed.
Lesson 112 763