Calculation involving complex numbers and modules












0












$begingroup$


I have been racking my brain about the following for an hour now, to no avail… Can anyone help out, or at least tell me the first couple of steps in resolving this?



$z$ is a complex number and $n geq 1$ is a natural number. It is given that |z|=2. Calculate the number $α=|z^n+overline z^n|^2+|z^n-overline z^n|^2$.



Thank you!










share|cite|improve this question











$endgroup$












  • $begingroup$
    Those seem reminiscent of the hyperbolic trig functions cosh and sinh. Have you tried something in that direction?
    $endgroup$
    – Fede Poncio
    Jan 27 at 22:50










  • $begingroup$
    Looks more like the ordinary trig functions to me, @Fede.
    $endgroup$
    – Gerry Myerson
    Jan 27 at 23:15










  • $begingroup$
    Yes, that’s what was on my mind. Sorry for the confusion!
    $endgroup$
    – Fede Poncio
    Jan 28 at 0:20










  • $begingroup$
    @FedePoncio Yes, the trig functions should be the idea, but I simply cannot work it out...
    $endgroup$
    – dalta
    Jan 28 at 6:40






  • 1




    $begingroup$
    @dalta it’s beacause $|z|=2$, so in polar coordinates then, $r=2$
    $endgroup$
    – Fede Poncio
    Jan 28 at 16:53
















0












$begingroup$


I have been racking my brain about the following for an hour now, to no avail… Can anyone help out, or at least tell me the first couple of steps in resolving this?



$z$ is a complex number and $n geq 1$ is a natural number. It is given that |z|=2. Calculate the number $α=|z^n+overline z^n|^2+|z^n-overline z^n|^2$.



Thank you!










share|cite|improve this question











$endgroup$












  • $begingroup$
    Those seem reminiscent of the hyperbolic trig functions cosh and sinh. Have you tried something in that direction?
    $endgroup$
    – Fede Poncio
    Jan 27 at 22:50










  • $begingroup$
    Looks more like the ordinary trig functions to me, @Fede.
    $endgroup$
    – Gerry Myerson
    Jan 27 at 23:15










  • $begingroup$
    Yes, that’s what was on my mind. Sorry for the confusion!
    $endgroup$
    – Fede Poncio
    Jan 28 at 0:20










  • $begingroup$
    @FedePoncio Yes, the trig functions should be the idea, but I simply cannot work it out...
    $endgroup$
    – dalta
    Jan 28 at 6:40






  • 1




    $begingroup$
    @dalta it’s beacause $|z|=2$, so in polar coordinates then, $r=2$
    $endgroup$
    – Fede Poncio
    Jan 28 at 16:53














0












0








0


2



$begingroup$


I have been racking my brain about the following for an hour now, to no avail… Can anyone help out, or at least tell me the first couple of steps in resolving this?



$z$ is a complex number and $n geq 1$ is a natural number. It is given that |z|=2. Calculate the number $α=|z^n+overline z^n|^2+|z^n-overline z^n|^2$.



Thank you!










share|cite|improve this question











$endgroup$




I have been racking my brain about the following for an hour now, to no avail… Can anyone help out, or at least tell me the first couple of steps in resolving this?



$z$ is a complex number and $n geq 1$ is a natural number. It is given that |z|=2. Calculate the number $α=|z^n+overline z^n|^2+|z^n-overline z^n|^2$.



Thank you!







complex-numbers






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 27 at 22:40









Eric Wofsey

190k14216349




190k14216349










asked Jan 27 at 22:34









daltadalta

1508




1508












  • $begingroup$
    Those seem reminiscent of the hyperbolic trig functions cosh and sinh. Have you tried something in that direction?
    $endgroup$
    – Fede Poncio
    Jan 27 at 22:50










  • $begingroup$
    Looks more like the ordinary trig functions to me, @Fede.
    $endgroup$
    – Gerry Myerson
    Jan 27 at 23:15










  • $begingroup$
    Yes, that’s what was on my mind. Sorry for the confusion!
    $endgroup$
    – Fede Poncio
    Jan 28 at 0:20










  • $begingroup$
    @FedePoncio Yes, the trig functions should be the idea, but I simply cannot work it out...
    $endgroup$
    – dalta
    Jan 28 at 6:40






  • 1




    $begingroup$
    @dalta it’s beacause $|z|=2$, so in polar coordinates then, $r=2$
    $endgroup$
    – Fede Poncio
    Jan 28 at 16:53


















  • $begingroup$
    Those seem reminiscent of the hyperbolic trig functions cosh and sinh. Have you tried something in that direction?
    $endgroup$
    – Fede Poncio
    Jan 27 at 22:50










  • $begingroup$
    Looks more like the ordinary trig functions to me, @Fede.
    $endgroup$
    – Gerry Myerson
    Jan 27 at 23:15










  • $begingroup$
    Yes, that’s what was on my mind. Sorry for the confusion!
    $endgroup$
    – Fede Poncio
    Jan 28 at 0:20










  • $begingroup$
    @FedePoncio Yes, the trig functions should be the idea, but I simply cannot work it out...
    $endgroup$
    – dalta
    Jan 28 at 6:40






  • 1




    $begingroup$
    @dalta it’s beacause $|z|=2$, so in polar coordinates then, $r=2$
    $endgroup$
    – Fede Poncio
    Jan 28 at 16:53
















$begingroup$
Those seem reminiscent of the hyperbolic trig functions cosh and sinh. Have you tried something in that direction?
$endgroup$
– Fede Poncio
Jan 27 at 22:50




$begingroup$
Those seem reminiscent of the hyperbolic trig functions cosh and sinh. Have you tried something in that direction?
$endgroup$
– Fede Poncio
Jan 27 at 22:50












$begingroup$
Looks more like the ordinary trig functions to me, @Fede.
$endgroup$
– Gerry Myerson
Jan 27 at 23:15




$begingroup$
Looks more like the ordinary trig functions to me, @Fede.
$endgroup$
– Gerry Myerson
Jan 27 at 23:15












$begingroup$
Yes, that’s what was on my mind. Sorry for the confusion!
$endgroup$
– Fede Poncio
Jan 28 at 0:20




$begingroup$
Yes, that’s what was on my mind. Sorry for the confusion!
$endgroup$
– Fede Poncio
Jan 28 at 0:20












$begingroup$
@FedePoncio Yes, the trig functions should be the idea, but I simply cannot work it out...
$endgroup$
– dalta
Jan 28 at 6:40




$begingroup$
@FedePoncio Yes, the trig functions should be the idea, but I simply cannot work it out...
$endgroup$
– dalta
Jan 28 at 6:40




1




1




$begingroup$
@dalta it’s beacause $|z|=2$, so in polar coordinates then, $r=2$
$endgroup$
– Fede Poncio
Jan 28 at 16:53




$begingroup$
@dalta it’s beacause $|z|=2$, so in polar coordinates then, $r=2$
$endgroup$
– Fede Poncio
Jan 28 at 16:53










0






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',
autoActivateHeartbeat: false,
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%2f3090207%2fcalculation-involving-complex-numbers-and-modules%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Mathematics Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3090207%2fcalculation-involving-complex-numbers-and-modules%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

Can a sorcerer learn a 5th-level spell early by creating spell slots using the Font of Magic feature?

Does disintegrating a polymorphed enemy still kill it after the 2018 errata?

A Topological Invariant for $pi_3(U(n))$