@tomleslie okay thanks a lot!

@tomleslie i already downloaded the direct search package and while i try to do this part:

vlist := convert(`union`*map*(indets, constr, 'name')[], list)

the result is not a list of variable like in your work. do you know why?

@tomleslie that's exactly what i want! haha i'm sorry if i pissed you off. I'm a new user of maple but that's not actually an excuse tho. Is there any syntax to simplify withhout doing it 111 times? thanks

@tomleslie Thanks for your detail explanation, you should be teacher or something then. Just for the "x" thing, i think i made a mistake while creating the "fungsikerugian" function. Because in my mind, the "x" in the index of qtopi and in the function:

"(1-(1-(psi1*exp(-((x+1)/m1)^(m1/sigma1))+psi2*(1-exp(-((x+1)/m2)^(-m2/sigma2)))+psi3*exp(exp(-m3/sigma3)-exp((x+1-m3)/sigma3)))/(psi1*exp(-(x/m1)^(m1/sigma1))+psi2*(1-exp(-(x/m2)^(-m2/sigma2)))+psi3*exp(exp(-m3/sigma3)-exp((x-m3)/sigma3)))))"

should have same value simultaneously as the sigma/summation move. But it seems like there is a difference between them so how can i solve it? thanks again

@tomleslie i want to understand more about the syntax that you use. sorry i ask to much while you already help me a lot.

soln:=DirectSearch:-Search( fungsikerugian,
                              convert(constr, list),          --------> what is this about?
                              variables = vlist,                --------> what is this about?
                              assume=positive,              --------> what is this about?
                              evaluationlimit = 1000000 --------> what is this about?

i want to really understand this not just to finish my work so please enlighten me. I appreciate it so much 

@tomleslie i want to ask you something. In the final result you've sent to me, i find out  that x has a value. Actually i'm not looking for it and i thought it should give me different result than i expected if x has a value. I just use the x as the index of the sigma and the range value of x is 0..111. Perhaps you can help me more here

@tomleslie i've been looking for directsearch package in maple application but i can't find it. is there any key word or link that i can use?

@tomleslie @Mac Dude 907  thanks for your suggestions guys. I learn a lot. Special thanks for you @tomleslie for giving me your work and explanation, its absolutely helpful. God bless!

@tomleslie so i have to define x first? i already made my problem as a question and without picture, perhaps if you want to try workin on it. here is the link http://www.mapleprimes.com/questions/220931-Error-in-OptimizationNLPSolve-Could-Not-Store-HFloat?sq=220931

@tomleslie i'm new here so i just try to post it. i will do a question then. Thanks for your suggestions!