SOLUTION: By graphing the function on your calculator (TI-83) find the solutions of 1.2x^2 - 3.1x -4.5=0 to three decimal places. Explain how answer was obtained.

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: By graphing the function on your calculator (TI-83) find the solutions of 1.2x^2 - 3.1x -4.5=0 to three decimal places. Explain how answer was obtained.      Log On


   

Question 551780: By graphing the function on your calculator (TI-83) find the solutions of 1.2x^2 - 3.1x -4.5=0 to three decimal places. Explain how answer was obtained.
Found 2 solutions by richard1234, Edwin McCravy:
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
The best way is probably to trace the function and find the points where the graph meets the x-axis. Additionally, you could use the "solve" function or Newton's method. You should obtain x = -1.036 and x = 3.619 as your roots.

Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
1.2x^2 - 3.1x -4.5=0

Press ON
Press CLEAR
Press Y=

After \Y1 and after \Y2 type so that you see this

         \Y1=1.2X^2-3.1X-4.5
         \Y2=0  

Press ZOOM
Press 6
Press 2ND
Press TRACE
Press 5
Press ENTER
Press ENTER
Press ENTER

Read at bottom of screen

X=-1.03608   Y=0

One zero is -1.03608

Press 2ND
Press TRACE
Press 5
Press ENTER
Press ENTER
Press right arrow 15 times to get cursor nearer to other zero
Press ENTER

Read at bottom of screen

X= 3.619413   Y=0

The other zero is 3.619413

Edwin