How to get the inflection points for this function.?

fprime_expr:=x^sin(x)*(cos(x)*ln(x)+sin(x)/x);

i tried symbolic and numeric , but no answer 

for X:= solve( fprime_expr =0, x);

The array ( a 3 by 4 )  has elements:

1,1,1,1

2,4,8,16

3 ,9,27,81

How to do this a nested loop ? : how to reasoning this in Maple with do loops 

The plot is not showing two lines perpendicular ?

Bought this book way back in 2000 to learn programming in Maple for procedures.

Problem was that i could not test myself with the exercises, because there were no answers included 

Has someone answers in Maple from these exercises ? 

That is the only way to learn from this book and check my knowledge about programming.

Jan 

Years ago i used maple as in a worksheet

Nowadys there are two ways to use Maple: in document mode and worksheet mode ?

Very confusing this and it seems that the old worksheet mode has nothing to do with the document mode
 

Now in Maple i don't now how to use the worksheet mode anymore.
Can this worksheet mode used togehter with the document mode?

This is real troublesome exercise  to use Maple, why should i use the document mode and offers it the same functionality as in the worksheet mode ?