Find value of a with given angle












-1












$begingroup$


The equations of the line $L$ and the plane $Pi$ are as follows:



$$
L: qquad x-5=-(y+1); z = 4
$$

$$
Pi : qquad alpha x + z = 5alpha +4
$$

where $alpha$ is a constant.



If the angle between the line $L$ and $Pi$ is $pi/6$, what is the value of $alpha$?



There are two answers, one positive and negative, but the answers I got is only negative. Any help please. Thanking you guys in advanced :D










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    can you include your working?
    $endgroup$
    – Siong Thye Goh
    Jan 17 at 13:02










  • $begingroup$
    @SiongThyeGoh ibb.co/6t3PkD1 sorry the answer i got was a negative
    $endgroup$
    – Master Irfan Elahee
    Jan 17 at 13:06






  • 1




    $begingroup$
    please learn mathjax and type out your attempt in the question.
    $endgroup$
    – Siong Thye Goh
    Jan 17 at 13:23










  • $begingroup$
    will do :D thanks
    $endgroup$
    – Master Irfan Elahee
    Jan 17 at 13:29
















-1












$begingroup$


The equations of the line $L$ and the plane $Pi$ are as follows:



$$
L: qquad x-5=-(y+1); z = 4
$$

$$
Pi : qquad alpha x + z = 5alpha +4
$$

where $alpha$ is a constant.



If the angle between the line $L$ and $Pi$ is $pi/6$, what is the value of $alpha$?



There are two answers, one positive and negative, but the answers I got is only negative. Any help please. Thanking you guys in advanced :D










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    can you include your working?
    $endgroup$
    – Siong Thye Goh
    Jan 17 at 13:02










  • $begingroup$
    @SiongThyeGoh ibb.co/6t3PkD1 sorry the answer i got was a negative
    $endgroup$
    – Master Irfan Elahee
    Jan 17 at 13:06






  • 1




    $begingroup$
    please learn mathjax and type out your attempt in the question.
    $endgroup$
    – Siong Thye Goh
    Jan 17 at 13:23










  • $begingroup$
    will do :D thanks
    $endgroup$
    – Master Irfan Elahee
    Jan 17 at 13:29














-1












-1








-1





$begingroup$


The equations of the line $L$ and the plane $Pi$ are as follows:



$$
L: qquad x-5=-(y+1); z = 4
$$

$$
Pi : qquad alpha x + z = 5alpha +4
$$

where $alpha$ is a constant.



If the angle between the line $L$ and $Pi$ is $pi/6$, what is the value of $alpha$?



There are two answers, one positive and negative, but the answers I got is only negative. Any help please. Thanking you guys in advanced :D










share|cite|improve this question











$endgroup$




The equations of the line $L$ and the plane $Pi$ are as follows:



$$
L: qquad x-5=-(y+1); z = 4
$$

$$
Pi : qquad alpha x + z = 5alpha +4
$$

where $alpha$ is a constant.



If the angle between the line $L$ and $Pi$ is $pi/6$, what is the value of $alpha$?



There are two answers, one positive and negative, but the answers I got is only negative. Any help please. Thanking you guys in advanced :D







geometry






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 17 at 13:15









idriskameni

749321




749321










asked Jan 17 at 13:00









Master Irfan ElaheeMaster Irfan Elahee

13




13








  • 2




    $begingroup$
    can you include your working?
    $endgroup$
    – Siong Thye Goh
    Jan 17 at 13:02










  • $begingroup$
    @SiongThyeGoh ibb.co/6t3PkD1 sorry the answer i got was a negative
    $endgroup$
    – Master Irfan Elahee
    Jan 17 at 13:06






  • 1




    $begingroup$
    please learn mathjax and type out your attempt in the question.
    $endgroup$
    – Siong Thye Goh
    Jan 17 at 13:23










  • $begingroup$
    will do :D thanks
    $endgroup$
    – Master Irfan Elahee
    Jan 17 at 13:29














  • 2




    $begingroup$
    can you include your working?
    $endgroup$
    – Siong Thye Goh
    Jan 17 at 13:02










  • $begingroup$
    @SiongThyeGoh ibb.co/6t3PkD1 sorry the answer i got was a negative
    $endgroup$
    – Master Irfan Elahee
    Jan 17 at 13:06






  • 1




    $begingroup$
    please learn mathjax and type out your attempt in the question.
    $endgroup$
    – Siong Thye Goh
    Jan 17 at 13:23










  • $begingroup$
    will do :D thanks
    $endgroup$
    – Master Irfan Elahee
    Jan 17 at 13:29








2




2




$begingroup$
can you include your working?
$endgroup$
– Siong Thye Goh
Jan 17 at 13:02




$begingroup$
can you include your working?
$endgroup$
– Siong Thye Goh
Jan 17 at 13:02












$begingroup$
@SiongThyeGoh ibb.co/6t3PkD1 sorry the answer i got was a negative
$endgroup$
– Master Irfan Elahee
Jan 17 at 13:06




$begingroup$
@SiongThyeGoh ibb.co/6t3PkD1 sorry the answer i got was a negative
$endgroup$
– Master Irfan Elahee
Jan 17 at 13:06




1




1




$begingroup$
please learn mathjax and type out your attempt in the question.
$endgroup$
– Siong Thye Goh
Jan 17 at 13:23




$begingroup$
please learn mathjax and type out your attempt in the question.
$endgroup$
– Siong Thye Goh
Jan 17 at 13:23












$begingroup$
will do :D thanks
$endgroup$
– Master Irfan Elahee
Jan 17 at 13:29




$begingroup$
will do :D thanks
$endgroup$
– Master Irfan Elahee
Jan 17 at 13:29










1 Answer
1






active

oldest

votes


















0












$begingroup$

$$L:begin{pmatrix} x \ y \ zend{pmatrix}=begin{pmatrix} 5 \ -1 \ 4end{pmatrix}+ lambda begin{pmatrix}1 \ -1\ 0 end{pmatrix}$$



$$frac{|langle(1,-1,0),(alpha, 0,1)rangle|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



$$frac{|alpha|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



Hopefully you can solve for $alpha$ to obtain one positive and one negative value of $alpha$ from here.






share|cite|improve this answer









$endgroup$














    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
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3076937%2ffind-value-of-a-with-given-angle%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












    $begingroup$

    $$L:begin{pmatrix} x \ y \ zend{pmatrix}=begin{pmatrix} 5 \ -1 \ 4end{pmatrix}+ lambda begin{pmatrix}1 \ -1\ 0 end{pmatrix}$$



    $$frac{|langle(1,-1,0),(alpha, 0,1)rangle|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



    $$frac{|alpha|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



    Hopefully you can solve for $alpha$ to obtain one positive and one negative value of $alpha$ from here.






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      $$L:begin{pmatrix} x \ y \ zend{pmatrix}=begin{pmatrix} 5 \ -1 \ 4end{pmatrix}+ lambda begin{pmatrix}1 \ -1\ 0 end{pmatrix}$$



      $$frac{|langle(1,-1,0),(alpha, 0,1)rangle|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



      $$frac{|alpha|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



      Hopefully you can solve for $alpha$ to obtain one positive and one negative value of $alpha$ from here.






      share|cite|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        $$L:begin{pmatrix} x \ y \ zend{pmatrix}=begin{pmatrix} 5 \ -1 \ 4end{pmatrix}+ lambda begin{pmatrix}1 \ -1\ 0 end{pmatrix}$$



        $$frac{|langle(1,-1,0),(alpha, 0,1)rangle|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



        $$frac{|alpha|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



        Hopefully you can solve for $alpha$ to obtain one positive and one negative value of $alpha$ from here.






        share|cite|improve this answer









        $endgroup$



        $$L:begin{pmatrix} x \ y \ zend{pmatrix}=begin{pmatrix} 5 \ -1 \ 4end{pmatrix}+ lambda begin{pmatrix}1 \ -1\ 0 end{pmatrix}$$



        $$frac{|langle(1,-1,0),(alpha, 0,1)rangle|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



        $$frac{|alpha|}{sqrt2cdot sqrt{alpha^2+1}}=cosfrac{pi}6$$



        Hopefully you can solve for $alpha$ to obtain one positive and one negative value of $alpha$ from here.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 17 at 13:20









        Siong Thye GohSiong Thye Goh

        104k1468120




        104k1468120






























            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%2f3076937%2ffind-value-of-a-with-given-angle%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

            Human spaceflight

            Can not write log (Is /dev/pts mounted?) - openpty in Ubuntu-on-Windows?

            File:DeusFollowingSea.jpg