use a graphing utility to graph f(x)=0.2x^4+0.2x^3-0.9x^2+5 on the interval (-3,2) and approximate any local maxima and local minima

Question

determine where f is increasing and where it is decreasing

 

using a graphing utilty, graph the function for -3<x<2 and -5<y<10. 

Answer 1

On your graphing calculator, press the Y= button.  Begin typing your function.

 

\Y₁ = 0.2X^4 + 0.2X^3 - 0.9X^2 + 5

 

Now, we have a domain and range condition.  Go to WINDOW.  Set these parameters:

 

Xmin = -3

Xmax = 2

Ymin = -5

Ymax = 10

 

Press ENTER and then press GRAPH.  You will see the graph constructing on your calculator.

 

Next, is to get the local max and local minimum.  Press the 2ND, then hit TRACE.  

 

Choose option 3 to find the minimum

Choose option 4 to find the maximum

 

It will ask you to pick numbers for your boundaries.  Guess these numbers that surround the maximum or minimum.  Press ENTER. 

 

Your local minimum and local maximum points will display on the graphing screen.

 

 

Have fun with the calculator!

Answer 2

Using a graphing utility - WolframAlpha,com - the local maximum is (0, 5), and global minimum is at approximately x = -2.