relation between planes of a infinitesimal tetrahedron
$begingroup$
In relation to the tetrahedron depicted, the book I'm reading says that this relation between its surfaces holds:
$dsigma_i = dsigma_n cos(mathbf{n}, x_i) = n_i dsigma_m$
I don't understand how to derive it. If n is the unit exterior normal to the surface, (as the book defines it) then $n_i$ should be equal to 1, leading to $dsigma_i = 1cdot dsigma_m$
geometry trigonometry
$endgroup$
add a comment |
$begingroup$
In relation to the tetrahedron depicted, the book I'm reading says that this relation between its surfaces holds:
$dsigma_i = dsigma_n cos(mathbf{n}, x_i) = n_i dsigma_m$
I don't understand how to derive it. If n is the unit exterior normal to the surface, (as the book defines it) then $n_i$ should be equal to 1, leading to $dsigma_i = 1cdot dsigma_m$
geometry trigonometry
$endgroup$
$begingroup$
I think $n_i$ is the component of $mathbf{n}$ along axis $x_i$.
$endgroup$
– Aretino
Feb 3 at 10:56
add a comment |
$begingroup$
In relation to the tetrahedron depicted, the book I'm reading says that this relation between its surfaces holds:
$dsigma_i = dsigma_n cos(mathbf{n}, x_i) = n_i dsigma_m$
I don't understand how to derive it. If n is the unit exterior normal to the surface, (as the book defines it) then $n_i$ should be equal to 1, leading to $dsigma_i = 1cdot dsigma_m$
geometry trigonometry
$endgroup$
In relation to the tetrahedron depicted, the book I'm reading says that this relation between its surfaces holds:
$dsigma_i = dsigma_n cos(mathbf{n}, x_i) = n_i dsigma_m$
I don't understand how to derive it. If n is the unit exterior normal to the surface, (as the book defines it) then $n_i$ should be equal to 1, leading to $dsigma_i = 1cdot dsigma_m$
geometry trigonometry
geometry trigonometry
edited Feb 3 at 9:20
Giuliano Malatesta
asked Feb 3 at 9:12
Giuliano MalatestaGiuliano Malatesta
347
347
$begingroup$
I think $n_i$ is the component of $mathbf{n}$ along axis $x_i$.
$endgroup$
– Aretino
Feb 3 at 10:56
add a comment |
$begingroup$
I think $n_i$ is the component of $mathbf{n}$ along axis $x_i$.
$endgroup$
– Aretino
Feb 3 at 10:56
$begingroup$
I think $n_i$ is the component of $mathbf{n}$ along axis $x_i$.
$endgroup$
– Aretino
Feb 3 at 10:56
$begingroup$
I think $n_i$ is the component of $mathbf{n}$ along axis $x_i$.
$endgroup$
– Aretino
Feb 3 at 10:56
add a comment |
0
active
oldest
votes
Your Answer
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
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3098342%2frelation-between-planes-of-a-infinitesimal-tetrahedron%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
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.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3098342%2frelation-between-planes-of-a-infinitesimal-tetrahedron%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
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
$begingroup$
I think $n_i$ is the component of $mathbf{n}$ along axis $x_i$.
$endgroup$
– Aretino
Feb 3 at 10:56