janhardo

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These are replies submitted by janhardo

@Carl Love 

Thanks

I made a overhaul of task 1c and get stuck for drawing cross-hatching one symmetry part of the graph. 

Also i used a piecewise function A__right , but don't understand it  

All integrals ( symbolic, numeric (Int and int ) give the same answer

 

  Don't know yet why the lines are not perpendicular 

 

  


 

 

 

      

restart;

f:=x->x^5-2*x^3-4*x^2+x+4;

proc (x) options operator, arrow; x^5-2*x^3-4*x^2+x+4 end proc

(1)

p:= plot(f(x),x=-1..2,color=magenta,thickness=2,tickmarks=[3,3],gridlines= false);

 

with(plots,display);

[display]

(2)

a:=-0.4;b:=2;c:=-1;

-.4

 

2

 

-1

(3)

#f(a)+m*(x-a);

f1:=D(f);

proc (x) options operator, arrow; 5*x^4-6*x^2-8*x+1 end proc

(4)

mtan:=D(f)(a);

3.3680

(5)

tangentline:=plot(f(a)+mtan*(x-a),x=c..b,thickness=2,color=black,gridlines= false):

display({tangentline,p});

 

 

Now a normalline drawing in inflection point tangent line  

mnor:=-1/mtan;

-.2969121140

(6)

mtan*mnor;

-1.000000000

(7)

normalline :=plot(f(a)-mnor*(x-a),x=c..b,thickness=2,color=black,gridlines= false):

 

``

display({tangentline,normalline,p});

 

 

 


Download betounes_ex_set_1_andereaanpak_1_opg_5.mw

@fyi

Thanks

That's in one command, but like it more do in steps like in this example , because its about the how to come on this answer as you doing it by hand .
If maple can come up with a answer that's fantastic.

 

@acer

Thanks  

Its also not possible to add a enclosed section in a worksheet and posted here ? ..
 


 

 

 

Reading the task this critical points are stationary points ( function derative is zero) + inflection point
lets graph.

restart; with(plots):

f1:= 4*sin(x^3)-x^2;intvx:= x =-2..2;

4*sin(x^3)-x^2

 

x = -2 .. 2

(1)

plot(f1, intvx);

 

 

Easier to work in Maple with deratives is with the D operator seems

f2:=D(f1);

4*D(sin(x^3))-2*D(x)*x

(2)

 

Seems to be no easy derative to get with the D operator, then with the diff ( )
diff as expression or function input
lets try the function input.

 

restart;

f3:=x->4*sin(x^3)-x^2;

proc (x) options operator, arrow; 4*sin(x^3)-x^2 end proc

(3)

diff(f3(x),x);

12*x^2*cos(x^3)-2*x

(4)

Diff(f3(x),x):%=value(%);

Diff(4*sin(x^3)-x^2, x) = 12*x^2*cos(x^3)-2*x

(5)

# Diff(f1,x):% = value(%);

 

go back to (4)


 

Download exercise_set_1_task4.mw

 

@Carl Love 

Thanks

Some questions

1) 

plots:-display(plots,plot);

 (never seen before) is it a existing command ?

2) int(f-g)     

Why subtraction ?

------------------------------------------------------

I go to the next exercise set 1_3

 

@janhardo 

There was een example in the book enclosed

https://drive.google.com/open?id=1_FZN4k3_tZn8DSse1uKPnG9d1SVtfFPo

 

@Carl Love 

I got this now:

f := x^sin(x);
                                sin(x)
                          f := x     
g := x^cos(x);
                                cos(x)
                          g := x     
evalf(Int(abs(f-g), x= 1..15));
                          50.57916030
Its a powerful command, but that's probably not the solution asked by the author of the exercises.?  

 

@vv 

Its a difficult one

- intersections points of the two graphs :
How to do this ?: with a expression or in function notation
- calculate areas between intersection points

 

@Carl Love 

Thanks

For the worked out answers : my initial approach  was find interceptions with the x-axis and integrate the graph areas one by one.
With int (piecewise ,.. )   its be done faster and easier.

@vv 

Thanks

I can add the  math question in the worksheet too.

@janhardo 

When iwas doing the first excercise , i realized that there were no answer for checking my solutions

Can't expect that user here are willing to work out all the excercises for me
I think i was too enthusiastic, but working on the first exercise makes again clear for me that this is not a book for self-study

So i must stop my attempt to learn from this book
Its only useful if the answer of the excercises were provided on the cd-rom

Well thanks for the support!

Note: also possible with this old book that is is obsolete for the math in Maple 
So learning programming in Maple is now useful with a self -study book what not is aged, but there are not such books i think.  

@Rouben Rostamian  

Yes, i do want to start with : Exercise set_1 

@ecterrab 

Thanks for your answer

Maybe a simplification in Maple to cancel those input modes naming and replace them and call them output modes

How do you want to see as users your written (typed) mathematics on your screen  : as 1D output or as 2D output ?

Keep it simple.

 

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