equality in integral inequality for compelx functions











up vote
2
down vote

favorite












I am trying to understand why:



$left|displaystyle{int}_{gamma}fleft(zright)dzright|=displaystyle{int}_{gamma}left|fleft(zright)right||dz|iffforall z$ on $gamma$ it is $text{arg}left(fleft(zright)right)=text{const.}$



where $int_gamma f(z)|dz|:=int_a^bf(gamma(t))|gamma'(t)|dt$



can someone direct me? Thank you.










share|cite|improve this question
























  • That identity is for some $gamma$ or for all $gamma$?
    – ajotatxe
    yesterday










  • @ajotatxe $gamma$ is a path, any path
    – user3708158
    yesterday

















up vote
2
down vote

favorite












I am trying to understand why:



$left|displaystyle{int}_{gamma}fleft(zright)dzright|=displaystyle{int}_{gamma}left|fleft(zright)right||dz|iffforall z$ on $gamma$ it is $text{arg}left(fleft(zright)right)=text{const.}$



where $int_gamma f(z)|dz|:=int_a^bf(gamma(t))|gamma'(t)|dt$



can someone direct me? Thank you.










share|cite|improve this question
























  • That identity is for some $gamma$ or for all $gamma$?
    – ajotatxe
    yesterday










  • @ajotatxe $gamma$ is a path, any path
    – user3708158
    yesterday















up vote
2
down vote

favorite









up vote
2
down vote

favorite











I am trying to understand why:



$left|displaystyle{int}_{gamma}fleft(zright)dzright|=displaystyle{int}_{gamma}left|fleft(zright)right||dz|iffforall z$ on $gamma$ it is $text{arg}left(fleft(zright)right)=text{const.}$



where $int_gamma f(z)|dz|:=int_a^bf(gamma(t))|gamma'(t)|dt$



can someone direct me? Thank you.










share|cite|improve this question















I am trying to understand why:



$left|displaystyle{int}_{gamma}fleft(zright)dzright|=displaystyle{int}_{gamma}left|fleft(zright)right||dz|iffforall z$ on $gamma$ it is $text{arg}left(fleft(zright)right)=text{const.}$



where $int_gamma f(z)|dz|:=int_a^bf(gamma(t))|gamma'(t)|dt$



can someone direct me? Thank you.







integration complex-analysis complex-numbers complex-integration






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited 21 hours ago









JustDroppedIn

1,759419




1,759419










asked yesterday









user3708158

1066




1066












  • That identity is for some $gamma$ or for all $gamma$?
    – ajotatxe
    yesterday










  • @ajotatxe $gamma$ is a path, any path
    – user3708158
    yesterday




















  • That identity is for some $gamma$ or for all $gamma$?
    – ajotatxe
    yesterday










  • @ajotatxe $gamma$ is a path, any path
    – user3708158
    yesterday


















That identity is for some $gamma$ or for all $gamma$?
– ajotatxe
yesterday




That identity is for some $gamma$ or for all $gamma$?
– ajotatxe
yesterday












@ajotatxe $gamma$ is a path, any path
– user3708158
yesterday






@ajotatxe $gamma$ is a path, any path
– user3708158
yesterday

















active

oldest

votes











Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














 

draft saved


draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3005206%2fequality-in-integral-inequality-for-compelx-functions%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes
















 

draft saved


draft discarded



















































 


draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3005206%2fequality-in-integral-inequality-for-compelx-functions%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

'app-layout' is not a known element: how to share Component with different Modules

android studio warns about leanback feature tag usage required on manifest while using Unity exported app?

WPF add header to Image with URL pettitions [duplicate]