Express X in terms of x and z, Y in terms of y and z if
$begingroup$
Given
$$X+Y=x+y$$
$$X-Y=z(x-y)$$
where z is a positive constant.
Attempts so far
Its easy when $z=1$. I have tried shuffling the variables around trying to eliminate either $x$ or $y$ but I'm unsuccessful.I also tried to assume that $X=ax+bz+czx$,$Y=py+qz+rzy$ and tried to solve for $a,b,c$ but I couldn't.
algebra-precalculus
$endgroup$
add a comment |
$begingroup$
Given
$$X+Y=x+y$$
$$X-Y=z(x-y)$$
where z is a positive constant.
Attempts so far
Its easy when $z=1$. I have tried shuffling the variables around trying to eliminate either $x$ or $y$ but I'm unsuccessful.I also tried to assume that $X=ax+bz+czx$,$Y=py+qz+rzy$ and tried to solve for $a,b,c$ but I couldn't.
algebra-precalculus
$endgroup$
1
$begingroup$
I see that its easy when z=1. I have tried shuffling the variables around trying to eliminate either x or y but I'm unsuccessful.
$endgroup$
– user276750
Nov 29 '15 at 9:01
1
$begingroup$
I also tried to assume that X=ax+bz+czx and tried to solve for a,b,c but I couldn't
$endgroup$
– user276750
Nov 29 '15 at 9:02
$begingroup$
add your last comments to the question under "My attempt so far:"!
$endgroup$
– Jesse P Francis
Nov 29 '15 at 9:03
add a comment |
$begingroup$
Given
$$X+Y=x+y$$
$$X-Y=z(x-y)$$
where z is a positive constant.
Attempts so far
Its easy when $z=1$. I have tried shuffling the variables around trying to eliminate either $x$ or $y$ but I'm unsuccessful.I also tried to assume that $X=ax+bz+czx$,$Y=py+qz+rzy$ and tried to solve for $a,b,c$ but I couldn't.
algebra-precalculus
$endgroup$
Given
$$X+Y=x+y$$
$$X-Y=z(x-y)$$
where z is a positive constant.
Attempts so far
Its easy when $z=1$. I have tried shuffling the variables around trying to eliminate either $x$ or $y$ but I'm unsuccessful.I also tried to assume that $X=ax+bz+czx$,$Y=py+qz+rzy$ and tried to solve for $a,b,c$ but I couldn't.
algebra-precalculus
algebra-precalculus
edited Nov 29 '15 at 22:53
Daniel Robert-Nicoud
20.4k33696
20.4k33696
asked Nov 29 '15 at 8:45
user276750user276750
413
413
1
$begingroup$
I see that its easy when z=1. I have tried shuffling the variables around trying to eliminate either x or y but I'm unsuccessful.
$endgroup$
– user276750
Nov 29 '15 at 9:01
1
$begingroup$
I also tried to assume that X=ax+bz+czx and tried to solve for a,b,c but I couldn't
$endgroup$
– user276750
Nov 29 '15 at 9:02
$begingroup$
add your last comments to the question under "My attempt so far:"!
$endgroup$
– Jesse P Francis
Nov 29 '15 at 9:03
add a comment |
1
$begingroup$
I see that its easy when z=1. I have tried shuffling the variables around trying to eliminate either x or y but I'm unsuccessful.
$endgroup$
– user276750
Nov 29 '15 at 9:01
1
$begingroup$
I also tried to assume that X=ax+bz+czx and tried to solve for a,b,c but I couldn't
$endgroup$
– user276750
Nov 29 '15 at 9:02
$begingroup$
add your last comments to the question under "My attempt so far:"!
$endgroup$
– Jesse P Francis
Nov 29 '15 at 9:03
1
1
$begingroup$
I see that its easy when z=1. I have tried shuffling the variables around trying to eliminate either x or y but I'm unsuccessful.
$endgroup$
– user276750
Nov 29 '15 at 9:01
$begingroup$
I see that its easy when z=1. I have tried shuffling the variables around trying to eliminate either x or y but I'm unsuccessful.
$endgroup$
– user276750
Nov 29 '15 at 9:01
1
1
$begingroup$
I also tried to assume that X=ax+bz+czx and tried to solve for a,b,c but I couldn't
$endgroup$
– user276750
Nov 29 '15 at 9:02
$begingroup$
I also tried to assume that X=ax+bz+czx and tried to solve for a,b,c but I couldn't
$endgroup$
– user276750
Nov 29 '15 at 9:02
$begingroup$
add your last comments to the question under "My attempt so far:"!
$endgroup$
– Jesse P Francis
Nov 29 '15 at 9:03
$begingroup$
add your last comments to the question under "My attempt so far:"!
$endgroup$
– Jesse P Francis
Nov 29 '15 at 9:03
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Hint:
the solutions of the system are, for generic $z$:
$$
X=frac{x(1+z)+y(1-z)}{2} qquad
Y=frac{x(1-z)+y(1+z)}{2}
$$
so we can have $X=f(z,x)$ and $Y=f(z,y)$ only for $z=1$.
$endgroup$
$begingroup$
So you're saying unless z=1 we cannot express X as X=f(z,x)?
$endgroup$
– user276750
Nov 29 '15 at 9:27
$begingroup$
Yes, if $x$ and $y$ are independent.
$endgroup$
– Emilio Novati
Nov 29 '15 at 9:52
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%2f1551091%2fexpress-x-in-terms-of-x-and-z-y-in-terms-of-y-and-z-if%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Hint:
the solutions of the system are, for generic $z$:
$$
X=frac{x(1+z)+y(1-z)}{2} qquad
Y=frac{x(1-z)+y(1+z)}{2}
$$
so we can have $X=f(z,x)$ and $Y=f(z,y)$ only for $z=1$.
$endgroup$
$begingroup$
So you're saying unless z=1 we cannot express X as X=f(z,x)?
$endgroup$
– user276750
Nov 29 '15 at 9:27
$begingroup$
Yes, if $x$ and $y$ are independent.
$endgroup$
– Emilio Novati
Nov 29 '15 at 9:52
add a comment |
$begingroup$
Hint:
the solutions of the system are, for generic $z$:
$$
X=frac{x(1+z)+y(1-z)}{2} qquad
Y=frac{x(1-z)+y(1+z)}{2}
$$
so we can have $X=f(z,x)$ and $Y=f(z,y)$ only for $z=1$.
$endgroup$
$begingroup$
So you're saying unless z=1 we cannot express X as X=f(z,x)?
$endgroup$
– user276750
Nov 29 '15 at 9:27
$begingroup$
Yes, if $x$ and $y$ are independent.
$endgroup$
– Emilio Novati
Nov 29 '15 at 9:52
add a comment |
$begingroup$
Hint:
the solutions of the system are, for generic $z$:
$$
X=frac{x(1+z)+y(1-z)}{2} qquad
Y=frac{x(1-z)+y(1+z)}{2}
$$
so we can have $X=f(z,x)$ and $Y=f(z,y)$ only for $z=1$.
$endgroup$
Hint:
the solutions of the system are, for generic $z$:
$$
X=frac{x(1+z)+y(1-z)}{2} qquad
Y=frac{x(1-z)+y(1+z)}{2}
$$
so we can have $X=f(z,x)$ and $Y=f(z,y)$ only for $z=1$.
edited Nov 29 '15 at 9:19
answered Nov 29 '15 at 9:09
Emilio NovatiEmilio Novati
52k43474
52k43474
$begingroup$
So you're saying unless z=1 we cannot express X as X=f(z,x)?
$endgroup$
– user276750
Nov 29 '15 at 9:27
$begingroup$
Yes, if $x$ and $y$ are independent.
$endgroup$
– Emilio Novati
Nov 29 '15 at 9:52
add a comment |
$begingroup$
So you're saying unless z=1 we cannot express X as X=f(z,x)?
$endgroup$
– user276750
Nov 29 '15 at 9:27
$begingroup$
Yes, if $x$ and $y$ are independent.
$endgroup$
– Emilio Novati
Nov 29 '15 at 9:52
$begingroup$
So you're saying unless z=1 we cannot express X as X=f(z,x)?
$endgroup$
– user276750
Nov 29 '15 at 9:27
$begingroup$
So you're saying unless z=1 we cannot express X as X=f(z,x)?
$endgroup$
– user276750
Nov 29 '15 at 9:27
$begingroup$
Yes, if $x$ and $y$ are independent.
$endgroup$
– Emilio Novati
Nov 29 '15 at 9:52
$begingroup$
Yes, if $x$ and $y$ are independent.
$endgroup$
– Emilio Novati
Nov 29 '15 at 9:52
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%2f1551091%2fexpress-x-in-terms-of-x-and-z-y-in-terms-of-y-and-z-if%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
1
$begingroup$
I see that its easy when z=1. I have tried shuffling the variables around trying to eliminate either x or y but I'm unsuccessful.
$endgroup$
– user276750
Nov 29 '15 at 9:01
1
$begingroup$
I also tried to assume that X=ax+bz+czx and tried to solve for a,b,c but I couldn't
$endgroup$
– user276750
Nov 29 '15 at 9:02
$begingroup$
add your last comments to the question under "My attempt so far:"!
$endgroup$
– Jesse P Francis
Nov 29 '15 at 9:03