@Preben Alsholm what is going on internally here. nothing seems to happen here

According to this, it uses a remember table

https://en.wikibooks.org/wiki/Maple/Getting_Started#Defining_a_function_with_Maple

> f(x):=2*x+2;

defines f as a procedure with a "remember table" that is assigned only for the argument x:

> f(u);

and

> f(x)=2*x+2;

is an equation.

@Preben Alsholm And based on your example, we could say, evaluating functions comes before exponentiating (order of operations).

That is, x^2(3) = x^(2(3)) = x^(2) = x^2

So to answer the question above

> f:=x^2
> f(3)
why is output: x(3)^2

It is treating 'x' as a function, which we could have defined earlier.

In other words, f(3) = (x(3))^2 = x(3)^2

The only way to escape this is to insert a multiplication sign.

It is interesting that 2(3) evaluates to 2 treating it as a constant function. A proviso, this must be in maple input. In 2d math mode, 2(3) is assumed to be multiplication and evaluates to 6.

@Markiyan Hirnyk woops, i see now. thanks :)

@Markiyan Hirnyk I don't understand.

I an interested to see how Maple can help students learn new concepts.

In my experiencing using Maple lets you avoid tedious calculation so you have a clear idea of the target solution. It can also aid in the understanding of the manual calculations.

I have noticed that autoscroll does not work as well in maple 2015

also when i use autocomplete, it gets stuck

For example if I type

with(Student[VectorCalculus]

the cursor gets suck after the letter s and have to manually use mouse to get cursor after ] to close with parentheses.

This only happens in 2d math mode, not in 1d math mode.

But the 1d math mode does not always autoscroll down so I prefer not to use it either.

@vv 

i see, thankyou

and by 'parsed' what do you mean, that the software adds the smart operator?

im not familiar with this word

@vv 

ok is 1d math the same as maple notation http://prntscr.com/8vjur5

and 'maple input' http://prntscr.com/8vjv41

what is the advantage of using maple input versus 2d math

@vv 

I am using 1d math , I believe.

well it says 2d input in the drop down menu

how do you use 1d math.

http://prntscr.com/8vjqs9

@acer 

wow that did the trick

I unchecked 'smart operator' and applied globally. now it works.

so the smart operator treated 'D(f)(x)' as D(f)*(x)

still i wonder why with 'smart operator' enabled, it adds a space when you type D(f)(x) into the prompt,

so I see  D(f)  (x)   

this might be a clue http://prntscr.com/8vjsxx

if you put a space between (x-3)  (x-2) , maple treats it like (x-3)*(x-2)

without a space it treats it as , something else

@Adri van der Meer 

Your expression is correct but it doesn't address my problem.

The problem that I am having is that when I type 'D(f)(x) ' the software adds a space and writes 'D(f) (x)' and then i have to go back and manually delete the space. It might have something to do with the left parenthese.

take a look at this , it might be more clear

http://prntscr.com/8vji4k

do you see the space is larger between D(f) (x) , versus D(f)(x)

when I input it, it gives me an extra space

@tomleslie Thankyou for your reply.

Question. What is the exact difference between sort and collect. why do they work differently.

I have uploaded the document so you can view the differences. Here is a screenshot.

http://prntscr.com/8juzta

Here is the worksheet.

collect.mw

@Markiyan Hirnyk thankyou for youre reply

@Rouben Rostamian  

that seems work, thankyou.

but... there may be a situation where you can't use surd. I am looking for examples.

j:= x-> x^2.875

now i have problems with complex numbers

diff(j(x),x)

evalf(j(-2))  comes out complex answer

So i have to turn 2.875 into a rational number. 

I tried

j(-2) gave me

Oh nevermind, surd(x,8) is not defined for x<0 reals anyway.

which is complex

There are also possible problems if you raise a number to a square root

m:= x-> x^cuberoot 3

m(-2)

Also what exactly is the definition of the principal cube root of -1, it is necessarily a complex number?

I know the principal square root of 4 is 2.

Does (RealDomain); get you the same result with fractional exponents? I tried it and got a messy expression with signum's everywhere.

Also odd is the fact

evalf(surd(-2,8)) does not equal evalf((-2)^(1/8))

shouldn't they be equal since if x < 0 , the surd becomes complex

more observations:

does not simplify as well as your expression