The volume of two vertically stacked, diagonally halved unit cubes
$begingroup$
How do I express the volume of the painted area using multiple integrals? The answer should be $1$, because the volume is $0.5 times 2 times 1 times 1=1$.
integration volume
$endgroup$
add a comment |
$begingroup$
How do I express the volume of the painted area using multiple integrals? The answer should be $1$, because the volume is $0.5 times 2 times 1 times 1=1$.
integration volume
$endgroup$
add a comment |
$begingroup$
How do I express the volume of the painted area using multiple integrals? The answer should be $1$, because the volume is $0.5 times 2 times 1 times 1=1$.
integration volume
$endgroup$
How do I express the volume of the painted area using multiple integrals? The answer should be $1$, because the volume is $0.5 times 2 times 1 times 1=1$.
integration volume
integration volume
edited Jan 31 at 7:40
Mohammad Zuhair Khan
1,6892625
1,6892625
asked Jan 31 at 7:33
KimKim
62
62
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
It is obvious that $0leq z leq 2$.
Let $f(t)$ be the area of the intersection of red area and $z=t$.
Then the volume is $int_0^2 f(t) dt$.
the intersection of red area and $z=t$ is expressed as follows:
$$1- frac{1}{2}t leq x leq 1, ~~ 0 leq y leq 1.$$
Thus $f(t)$ is
$$ int_0^1 int_{1- frac{1}{2}t}^1 dx dy.$$
Hence, the volume is
$$int_0^2 int_0^1 int_{1- frac{1}{2}t}^1 dx dy dt =
int_0^2 int_0^1 int_{1- frac{1}{2}z}^1 dx dy dz.
$$
$endgroup$
add a comment |
$begingroup$
You can consider the cutting plane as graph of the function $f(x,y):=2x$ over the unit square $Q:=[0,1]times[0,1]$ in the $(x,y)$-plane. Your red set $B$ then has volume
$${rm vol}(B)=int_Q f(x,y)>{rm d}(x,y)=int_0^1int_0^1 2x >dy>dx=int_0^1 2x>dx=x^2biggr|_0^1=1 .$$
$endgroup$
add a comment |
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
});
}
});
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%2f3094619%2fthe-volume-of-two-vertically-stacked-diagonally-halved-unit-cubes%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
It is obvious that $0leq z leq 2$.
Let $f(t)$ be the area of the intersection of red area and $z=t$.
Then the volume is $int_0^2 f(t) dt$.
the intersection of red area and $z=t$ is expressed as follows:
$$1- frac{1}{2}t leq x leq 1, ~~ 0 leq y leq 1.$$
Thus $f(t)$ is
$$ int_0^1 int_{1- frac{1}{2}t}^1 dx dy.$$
Hence, the volume is
$$int_0^2 int_0^1 int_{1- frac{1}{2}t}^1 dx dy dt =
int_0^2 int_0^1 int_{1- frac{1}{2}z}^1 dx dy dz.
$$
$endgroup$
add a comment |
$begingroup$
It is obvious that $0leq z leq 2$.
Let $f(t)$ be the area of the intersection of red area and $z=t$.
Then the volume is $int_0^2 f(t) dt$.
the intersection of red area and $z=t$ is expressed as follows:
$$1- frac{1}{2}t leq x leq 1, ~~ 0 leq y leq 1.$$
Thus $f(t)$ is
$$ int_0^1 int_{1- frac{1}{2}t}^1 dx dy.$$
Hence, the volume is
$$int_0^2 int_0^1 int_{1- frac{1}{2}t}^1 dx dy dt =
int_0^2 int_0^1 int_{1- frac{1}{2}z}^1 dx dy dz.
$$
$endgroup$
add a comment |
$begingroup$
It is obvious that $0leq z leq 2$.
Let $f(t)$ be the area of the intersection of red area and $z=t$.
Then the volume is $int_0^2 f(t) dt$.
the intersection of red area and $z=t$ is expressed as follows:
$$1- frac{1}{2}t leq x leq 1, ~~ 0 leq y leq 1.$$
Thus $f(t)$ is
$$ int_0^1 int_{1- frac{1}{2}t}^1 dx dy.$$
Hence, the volume is
$$int_0^2 int_0^1 int_{1- frac{1}{2}t}^1 dx dy dt =
int_0^2 int_0^1 int_{1- frac{1}{2}z}^1 dx dy dz.
$$
$endgroup$
It is obvious that $0leq z leq 2$.
Let $f(t)$ be the area of the intersection of red area and $z=t$.
Then the volume is $int_0^2 f(t) dt$.
the intersection of red area and $z=t$ is expressed as follows:
$$1- frac{1}{2}t leq x leq 1, ~~ 0 leq y leq 1.$$
Thus $f(t)$ is
$$ int_0^1 int_{1- frac{1}{2}t}^1 dx dy.$$
Hence, the volume is
$$int_0^2 int_0^1 int_{1- frac{1}{2}t}^1 dx dy dt =
int_0^2 int_0^1 int_{1- frac{1}{2}z}^1 dx dy dz.
$$
answered Jan 31 at 8:24
Doyun NamDoyun Nam
66619
66619
add a comment |
add a comment |
$begingroup$
You can consider the cutting plane as graph of the function $f(x,y):=2x$ over the unit square $Q:=[0,1]times[0,1]$ in the $(x,y)$-plane. Your red set $B$ then has volume
$${rm vol}(B)=int_Q f(x,y)>{rm d}(x,y)=int_0^1int_0^1 2x >dy>dx=int_0^1 2x>dx=x^2biggr|_0^1=1 .$$
$endgroup$
add a comment |
$begingroup$
You can consider the cutting plane as graph of the function $f(x,y):=2x$ over the unit square $Q:=[0,1]times[0,1]$ in the $(x,y)$-plane. Your red set $B$ then has volume
$${rm vol}(B)=int_Q f(x,y)>{rm d}(x,y)=int_0^1int_0^1 2x >dy>dx=int_0^1 2x>dx=x^2biggr|_0^1=1 .$$
$endgroup$
add a comment |
$begingroup$
You can consider the cutting plane as graph of the function $f(x,y):=2x$ over the unit square $Q:=[0,1]times[0,1]$ in the $(x,y)$-plane. Your red set $B$ then has volume
$${rm vol}(B)=int_Q f(x,y)>{rm d}(x,y)=int_0^1int_0^1 2x >dy>dx=int_0^1 2x>dx=x^2biggr|_0^1=1 .$$
$endgroup$
You can consider the cutting plane as graph of the function $f(x,y):=2x$ over the unit square $Q:=[0,1]times[0,1]$ in the $(x,y)$-plane. Your red set $B$ then has volume
$${rm vol}(B)=int_Q f(x,y)>{rm d}(x,y)=int_0^1int_0^1 2x >dy>dx=int_0^1 2x>dx=x^2biggr|_0^1=1 .$$
answered Jan 31 at 8:29
Christian BlatterChristian Blatter
176k8115328
176k8115328
add a comment |
add a comment |
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%2f3094619%2fthe-volume-of-two-vertically-stacked-diagonally-halved-unit-cubes%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