Finding parameters for which the line lies in the plane












0














I tried to solve the following task:
A line L has equation: $frac{x-2}{p} = frac{y-q}{2}= z-1$, where $p,q in mathbb{R} $. A plane P has equation: $ x +y +3z = 9$. Given that line L lies in the plane P, find the value of $p$ and the value of $q$.



In order to find $p$ and $q$, I did following: I found the parametric form of the line: $x = t p +2$, $ y = 2t +q$, $ z= t+1$, where $t in mathbb{R}$ and then, I inserted these values in the equation of P. I got this:



$(tp +2) + (2t +q) + 3(t+1) = 9$ or



$q +tp + 5t = 4$



Can I just insert now 2 arbitrary real values of $t$ and then solve the system of two linear equations to find $p$ and $q$? Is that correct approach? Thanks in advance.










share|cite|improve this question






















  • Isn't there more than one line having this equation that lie in the plane? Infinetly many maybe?
    – Fareed AF
    Dec 8 at 8:25
















0














I tried to solve the following task:
A line L has equation: $frac{x-2}{p} = frac{y-q}{2}= z-1$, where $p,q in mathbb{R} $. A plane P has equation: $ x +y +3z = 9$. Given that line L lies in the plane P, find the value of $p$ and the value of $q$.



In order to find $p$ and $q$, I did following: I found the parametric form of the line: $x = t p +2$, $ y = 2t +q$, $ z= t+1$, where $t in mathbb{R}$ and then, I inserted these values in the equation of P. I got this:



$(tp +2) + (2t +q) + 3(t+1) = 9$ or



$q +tp + 5t = 4$



Can I just insert now 2 arbitrary real values of $t$ and then solve the system of two linear equations to find $p$ and $q$? Is that correct approach? Thanks in advance.










share|cite|improve this question






















  • Isn't there more than one line having this equation that lie in the plane? Infinetly many maybe?
    – Fareed AF
    Dec 8 at 8:25














0












0








0







I tried to solve the following task:
A line L has equation: $frac{x-2}{p} = frac{y-q}{2}= z-1$, where $p,q in mathbb{R} $. A plane P has equation: $ x +y +3z = 9$. Given that line L lies in the plane P, find the value of $p$ and the value of $q$.



In order to find $p$ and $q$, I did following: I found the parametric form of the line: $x = t p +2$, $ y = 2t +q$, $ z= t+1$, where $t in mathbb{R}$ and then, I inserted these values in the equation of P. I got this:



$(tp +2) + (2t +q) + 3(t+1) = 9$ or



$q +tp + 5t = 4$



Can I just insert now 2 arbitrary real values of $t$ and then solve the system of two linear equations to find $p$ and $q$? Is that correct approach? Thanks in advance.










share|cite|improve this question













I tried to solve the following task:
A line L has equation: $frac{x-2}{p} = frac{y-q}{2}= z-1$, where $p,q in mathbb{R} $. A plane P has equation: $ x +y +3z = 9$. Given that line L lies in the plane P, find the value of $p$ and the value of $q$.



In order to find $p$ and $q$, I did following: I found the parametric form of the line: $x = t p +2$, $ y = 2t +q$, $ z= t+1$, where $t in mathbb{R}$ and then, I inserted these values in the equation of P. I got this:



$(tp +2) + (2t +q) + 3(t+1) = 9$ or



$q +tp + 5t = 4$



Can I just insert now 2 arbitrary real values of $t$ and then solve the system of two linear equations to find $p$ and $q$? Is that correct approach? Thanks in advance.







analytic-geometry plane-geometry






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 8 at 8:12









user121

273




273












  • Isn't there more than one line having this equation that lie in the plane? Infinetly many maybe?
    – Fareed AF
    Dec 8 at 8:25


















  • Isn't there more than one line having this equation that lie in the plane? Infinetly many maybe?
    – Fareed AF
    Dec 8 at 8:25
















Isn't there more than one line having this equation that lie in the plane? Infinetly many maybe?
– Fareed AF
Dec 8 at 8:25




Isn't there more than one line having this equation that lie in the plane? Infinetly many maybe?
– Fareed AF
Dec 8 at 8:25










1 Answer
1






active

oldest

votes


















0














Yes, you may do that. You can also note more directly, by comparing the coefficients of $t$, that $p,q$ are real constants, so the only way $t(p+5)=4-q, forall tinBbb R$ is when $p=-5, q=4$.



Another way to find $p,q$ would be to note that $(2,q,1)$ is a point on the line and hence on the plane $implies 2+q+3=9implies q=4$. Also note that the line is parallel to the free vector $(p,2,1)$, that must be perpendicular to the normal of the plane in order for the line to lie in the plane $implies (p,2,1)cdot(1,1,3)=0implies p=-5$.






share|cite|improve this answer























  • Great, thanks a lot!
    – user121
    Dec 8 at 9:34











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%2f3030819%2ffinding-parameters-for-which-the-line-lies-in-the-plane%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









0














Yes, you may do that. You can also note more directly, by comparing the coefficients of $t$, that $p,q$ are real constants, so the only way $t(p+5)=4-q, forall tinBbb R$ is when $p=-5, q=4$.



Another way to find $p,q$ would be to note that $(2,q,1)$ is a point on the line and hence on the plane $implies 2+q+3=9implies q=4$. Also note that the line is parallel to the free vector $(p,2,1)$, that must be perpendicular to the normal of the plane in order for the line to lie in the plane $implies (p,2,1)cdot(1,1,3)=0implies p=-5$.






share|cite|improve this answer























  • Great, thanks a lot!
    – user121
    Dec 8 at 9:34
















0














Yes, you may do that. You can also note more directly, by comparing the coefficients of $t$, that $p,q$ are real constants, so the only way $t(p+5)=4-q, forall tinBbb R$ is when $p=-5, q=4$.



Another way to find $p,q$ would be to note that $(2,q,1)$ is a point on the line and hence on the plane $implies 2+q+3=9implies q=4$. Also note that the line is parallel to the free vector $(p,2,1)$, that must be perpendicular to the normal of the plane in order for the line to lie in the plane $implies (p,2,1)cdot(1,1,3)=0implies p=-5$.






share|cite|improve this answer























  • Great, thanks a lot!
    – user121
    Dec 8 at 9:34














0












0








0






Yes, you may do that. You can also note more directly, by comparing the coefficients of $t$, that $p,q$ are real constants, so the only way $t(p+5)=4-q, forall tinBbb R$ is when $p=-5, q=4$.



Another way to find $p,q$ would be to note that $(2,q,1)$ is a point on the line and hence on the plane $implies 2+q+3=9implies q=4$. Also note that the line is parallel to the free vector $(p,2,1)$, that must be perpendicular to the normal of the plane in order for the line to lie in the plane $implies (p,2,1)cdot(1,1,3)=0implies p=-5$.






share|cite|improve this answer














Yes, you may do that. You can also note more directly, by comparing the coefficients of $t$, that $p,q$ are real constants, so the only way $t(p+5)=4-q, forall tinBbb R$ is when $p=-5, q=4$.



Another way to find $p,q$ would be to note that $(2,q,1)$ is a point on the line and hence on the plane $implies 2+q+3=9implies q=4$. Also note that the line is parallel to the free vector $(p,2,1)$, that must be perpendicular to the normal of the plane in order for the line to lie in the plane $implies (p,2,1)cdot(1,1,3)=0implies p=-5$.







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Dec 8 at 9:30

























answered Dec 8 at 9:22









Shubham Johri

3,861716




3,861716












  • Great, thanks a lot!
    – user121
    Dec 8 at 9:34


















  • Great, thanks a lot!
    – user121
    Dec 8 at 9:34
















Great, thanks a lot!
– user121
Dec 8 at 9:34




Great, thanks a lot!
– user121
Dec 8 at 9:34


















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.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • 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.


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%2f3030819%2ffinding-parameters-for-which-the-line-lies-in-the-plane%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

Måne

Storängen

VLT Carioca