finding a tangent line to a parabola Unicorn Meta Zoo #1: Why another podcast? Announcing the arrival of Valued Associate #679: Cesar ManaraHow do I find the equation of a tangent line to a curve?Find intersection(s) between parametrized parabola and a lineHow to find equation of tangent line to $x^2 = 2y$ at $(-3, 9/2)$Find the equation of parabola tangent to a lineWhy is this answer wrong? (point of intersection between parabola and line)Euclid 1999 Question 4(a) - Circle Tangent Intersection4 tangent lines to parabola with points on circleFinding the Equation for the Line Tangent to a Parabola At a Given PointMirror image of the parabola about a tangentMaximizing $x^2 y + y^2 z + z^2 x − x^2 z − y^2 x − z^2 y$ for $x$, $y$, $z$ between $0$ and $1$ (inclusive)Find the numerical value of this expression

Why does the Cisco show run command not show the full version, while the show version command does?

Check if a string is entirely made of the same substring

I preordered a game on my Xbox while on the home screen of my friend's account. Which of us owns the game?

What *exactly* is electrical current, voltage, and resistance?

Suing a Police Officer Instead of the Police Department

Protagonist's race is hidden - should I reveal it?

Has a Nobel Peace laureate ever been accused of war crimes?

Passing args from the bash script to the function in the script

What was Apollo 13's "Little Jolt" after MECO?

What is /etc/mtab in Linux?

Could Neutrino technically as side-effect, incentivize centralization of the bitcoin network?

Can you stand up from being prone using Skirmisher outside of your turn?

Is Diceware more secure than a long passphrase?

Raising a bilingual kid. When should we introduce the majority language?

How to keep bees out of canned beverages?

How do I check if a string is entirely made of the same substring?

Is there any hidden 'W' sound after 'comment' in : Comment est-elle?

How long after the last departure shall the airport stay open for an emergency return?

Is Electric Central Heating worth it if using Solar Panels?

Mistake in years of experience in resume?

The art of proof summarizing. Are there known rules, or is it a purely common sense matter?

c++ diamond problem - How to call base method only once

What to do with someone that cheated their way through university and a PhD program?

Book with legacy programming code on a space ship that the main character hacks to escape



finding a tangent line to a parabola



Unicorn Meta Zoo #1: Why another podcast?
Announcing the arrival of Valued Associate #679: Cesar ManaraHow do I find the equation of a tangent line to a curve?Find intersection(s) between parametrized parabola and a lineHow to find equation of tangent line to $x^2 = 2y$ at $(-3, 9/2)$Find the equation of parabola tangent to a lineWhy is this answer wrong? (point of intersection between parabola and line)Euclid 1999 Question 4(a) - Circle Tangent Intersection4 tangent lines to parabola with points on circleFinding the Equation for the Line Tangent to a Parabola At a Given PointMirror image of the parabola about a tangentMaximizing $x^2 y + y^2 z + z^2 x − x^2 z − y^2 x − z^2 y$ for $x$, $y$, $z$ between $0$ and $1$ (inclusive)Find the numerical value of this expression










3












$begingroup$


I am practicing for a math contest and I encountered the following problem that I don't know how to solve:



For which value of $b$ is there only one intersection between the line $y = x + b$ and the parabola $y = x^2 + 5x + 3$?



How do I solve it?










share|cite|improve this question









New contributor




swagbutton8 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$







  • 1




    $begingroup$
    Do you know how to find a derivative?
    $endgroup$
    – R. Burton
    5 hours ago






  • 1




    $begingroup$
    Simply $x^2+5x+3=x+b$ must have only one solution, i.e. $x^2+4x+(3-b)=0$ should have zero discriminant.
    $endgroup$
    – the_fox
    5 hours ago










  • $begingroup$
    A Parabola could have many tangent lines...However, it has only 1 min. value, may be this one is the one you are after. More here:desmos.com/calculator/zz7e1nwgf9 and here:info:math.stackexchange.com/questions/92165/…
    $endgroup$
    – NoChance
    5 hours ago







  • 1




    $begingroup$
    @NoChance Your observation would be relevant if the line’s equation were of the form $y=b$. The line in the problem is not horizontal, though.
    $endgroup$
    – amd
    3 hours ago






  • 1




    $begingroup$
    @NoChance If you’re going to to that route, then you want the one that has the same slope as the given line.
    $endgroup$
    – amd
    1 hour ago
















3












$begingroup$


I am practicing for a math contest and I encountered the following problem that I don't know how to solve:



For which value of $b$ is there only one intersection between the line $y = x + b$ and the parabola $y = x^2 + 5x + 3$?



How do I solve it?










share|cite|improve this question









New contributor




swagbutton8 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$







  • 1




    $begingroup$
    Do you know how to find a derivative?
    $endgroup$
    – R. Burton
    5 hours ago






  • 1




    $begingroup$
    Simply $x^2+5x+3=x+b$ must have only one solution, i.e. $x^2+4x+(3-b)=0$ should have zero discriminant.
    $endgroup$
    – the_fox
    5 hours ago










  • $begingroup$
    A Parabola could have many tangent lines...However, it has only 1 min. value, may be this one is the one you are after. More here:desmos.com/calculator/zz7e1nwgf9 and here:info:math.stackexchange.com/questions/92165/…
    $endgroup$
    – NoChance
    5 hours ago







  • 1




    $begingroup$
    @NoChance Your observation would be relevant if the line’s equation were of the form $y=b$. The line in the problem is not horizontal, though.
    $endgroup$
    – amd
    3 hours ago






  • 1




    $begingroup$
    @NoChance If you’re going to to that route, then you want the one that has the same slope as the given line.
    $endgroup$
    – amd
    1 hour ago














3












3








3


1



$begingroup$


I am practicing for a math contest and I encountered the following problem that I don't know how to solve:



For which value of $b$ is there only one intersection between the line $y = x + b$ and the parabola $y = x^2 + 5x + 3$?



How do I solve it?










share|cite|improve this question









New contributor




swagbutton8 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







$endgroup$




I am practicing for a math contest and I encountered the following problem that I don't know how to solve:



For which value of $b$ is there only one intersection between the line $y = x + b$ and the parabola $y = x^2 + 5x + 3$?



How do I solve it?







algebra-precalculus contest-math






share|cite|improve this question









New contributor




swagbutton8 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|cite|improve this question









New contributor




swagbutton8 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|cite|improve this question




share|cite|improve this question








edited 5 hours ago









NoChance

3,79221321




3,79221321






New contributor




swagbutton8 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 5 hours ago









swagbutton8swagbutton8

161




161




New contributor




swagbutton8 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





swagbutton8 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






swagbutton8 is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.







  • 1




    $begingroup$
    Do you know how to find a derivative?
    $endgroup$
    – R. Burton
    5 hours ago






  • 1




    $begingroup$
    Simply $x^2+5x+3=x+b$ must have only one solution, i.e. $x^2+4x+(3-b)=0$ should have zero discriminant.
    $endgroup$
    – the_fox
    5 hours ago










  • $begingroup$
    A Parabola could have many tangent lines...However, it has only 1 min. value, may be this one is the one you are after. More here:desmos.com/calculator/zz7e1nwgf9 and here:info:math.stackexchange.com/questions/92165/…
    $endgroup$
    – NoChance
    5 hours ago







  • 1




    $begingroup$
    @NoChance Your observation would be relevant if the line’s equation were of the form $y=b$. The line in the problem is not horizontal, though.
    $endgroup$
    – amd
    3 hours ago






  • 1




    $begingroup$
    @NoChance If you’re going to to that route, then you want the one that has the same slope as the given line.
    $endgroup$
    – amd
    1 hour ago













  • 1




    $begingroup$
    Do you know how to find a derivative?
    $endgroup$
    – R. Burton
    5 hours ago






  • 1




    $begingroup$
    Simply $x^2+5x+3=x+b$ must have only one solution, i.e. $x^2+4x+(3-b)=0$ should have zero discriminant.
    $endgroup$
    – the_fox
    5 hours ago










  • $begingroup$
    A Parabola could have many tangent lines...However, it has only 1 min. value, may be this one is the one you are after. More here:desmos.com/calculator/zz7e1nwgf9 and here:info:math.stackexchange.com/questions/92165/…
    $endgroup$
    – NoChance
    5 hours ago







  • 1




    $begingroup$
    @NoChance Your observation would be relevant if the line’s equation were of the form $y=b$. The line in the problem is not horizontal, though.
    $endgroup$
    – amd
    3 hours ago






  • 1




    $begingroup$
    @NoChance If you’re going to to that route, then you want the one that has the same slope as the given line.
    $endgroup$
    – amd
    1 hour ago








1




1




$begingroup$
Do you know how to find a derivative?
$endgroup$
– R. Burton
5 hours ago




$begingroup$
Do you know how to find a derivative?
$endgroup$
– R. Burton
5 hours ago




1




1




$begingroup$
Simply $x^2+5x+3=x+b$ must have only one solution, i.e. $x^2+4x+(3-b)=0$ should have zero discriminant.
$endgroup$
– the_fox
5 hours ago




$begingroup$
Simply $x^2+5x+3=x+b$ must have only one solution, i.e. $x^2+4x+(3-b)=0$ should have zero discriminant.
$endgroup$
– the_fox
5 hours ago












$begingroup$
A Parabola could have many tangent lines...However, it has only 1 min. value, may be this one is the one you are after. More here:desmos.com/calculator/zz7e1nwgf9 and here:info:math.stackexchange.com/questions/92165/…
$endgroup$
– NoChance
5 hours ago





$begingroup$
A Parabola could have many tangent lines...However, it has only 1 min. value, may be this one is the one you are after. More here:desmos.com/calculator/zz7e1nwgf9 and here:info:math.stackexchange.com/questions/92165/…
$endgroup$
– NoChance
5 hours ago





1




1




$begingroup$
@NoChance Your observation would be relevant if the line’s equation were of the form $y=b$. The line in the problem is not horizontal, though.
$endgroup$
– amd
3 hours ago




$begingroup$
@NoChance Your observation would be relevant if the line’s equation were of the form $y=b$. The line in the problem is not horizontal, though.
$endgroup$
– amd
3 hours ago




1




1




$begingroup$
@NoChance If you’re going to to that route, then you want the one that has the same slope as the given line.
$endgroup$
– amd
1 hour ago





$begingroup$
@NoChance If you’re going to to that route, then you want the one that has the same slope as the given line.
$endgroup$
– amd
1 hour ago











3 Answers
3






active

oldest

votes


















6












$begingroup$

Hint:
$$x^2+5x+3=x+biff x^2+4x+3-b=0,$$ this quadratic equation should have exactly one solution therefore the discriminant $Delta=?$






share|cite|improve this answer









$endgroup$




















    2












    $begingroup$

    The tangent to parabola has slope $y' = 2x+5$ which should be slope of line =1 at the point of contact. So point of contact is at x=-2. Substituting in parabola,we get y=-3. Now this point lies on line as well.






    share|cite|improve this answer









    $endgroup$




















      2












      $begingroup$

      Note that you like the line $y=x+b$ to be tangent to the parabola. The slope of this line is $ m=1.$ Thus the derivative of your parabola should be the same as the slope of the tangent line. Find the point of the tangency and find the $b$ value so that the line passes through that point.






      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
        );



        );






        swagbutton8 is a new contributor. Be nice, and check out our Code of Conduct.









        draft saved

        draft discarded


















        StackExchange.ready(
        function ()
        StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3201227%2ffinding-a-tangent-line-to-a-parabola%23new-answer', 'question_page');

        );

        Post as a guest















        Required, but never shown

























        3 Answers
        3






        active

        oldest

        votes








        3 Answers
        3






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        6












        $begingroup$

        Hint:
        $$x^2+5x+3=x+biff x^2+4x+3-b=0,$$ this quadratic equation should have exactly one solution therefore the discriminant $Delta=?$






        share|cite|improve this answer









        $endgroup$

















          6












          $begingroup$

          Hint:
          $$x^2+5x+3=x+biff x^2+4x+3-b=0,$$ this quadratic equation should have exactly one solution therefore the discriminant $Delta=?$






          share|cite|improve this answer









          $endgroup$















            6












            6








            6





            $begingroup$

            Hint:
            $$x^2+5x+3=x+biff x^2+4x+3-b=0,$$ this quadratic equation should have exactly one solution therefore the discriminant $Delta=?$






            share|cite|improve this answer









            $endgroup$



            Hint:
            $$x^2+5x+3=x+biff x^2+4x+3-b=0,$$ this quadratic equation should have exactly one solution therefore the discriminant $Delta=?$







            share|cite|improve this answer












            share|cite|improve this answer



            share|cite|improve this answer










            answered 5 hours ago









            HAMIDINE SOUMAREHAMIDINE SOUMARE

            3,1771422




            3,1771422





















                2












                $begingroup$

                The tangent to parabola has slope $y' = 2x+5$ which should be slope of line =1 at the point of contact. So point of contact is at x=-2. Substituting in parabola,we get y=-3. Now this point lies on line as well.






                share|cite|improve this answer









                $endgroup$

















                  2












                  $begingroup$

                  The tangent to parabola has slope $y' = 2x+5$ which should be slope of line =1 at the point of contact. So point of contact is at x=-2. Substituting in parabola,we get y=-3. Now this point lies on line as well.






                  share|cite|improve this answer









                  $endgroup$















                    2












                    2








                    2





                    $begingroup$

                    The tangent to parabola has slope $y' = 2x+5$ which should be slope of line =1 at the point of contact. So point of contact is at x=-2. Substituting in parabola,we get y=-3. Now this point lies on line as well.






                    share|cite|improve this answer









                    $endgroup$



                    The tangent to parabola has slope $y' = 2x+5$ which should be slope of line =1 at the point of contact. So point of contact is at x=-2. Substituting in parabola,we get y=-3. Now this point lies on line as well.







                    share|cite|improve this answer












                    share|cite|improve this answer



                    share|cite|improve this answer










                    answered 5 hours ago









                    TojrahTojrah

                    6188




                    6188





















                        2












                        $begingroup$

                        Note that you like the line $y=x+b$ to be tangent to the parabola. The slope of this line is $ m=1.$ Thus the derivative of your parabola should be the same as the slope of the tangent line. Find the point of the tangency and find the $b$ value so that the line passes through that point.






                        share|cite|improve this answer









                        $endgroup$

















                          2












                          $begingroup$

                          Note that you like the line $y=x+b$ to be tangent to the parabola. The slope of this line is $ m=1.$ Thus the derivative of your parabola should be the same as the slope of the tangent line. Find the point of the tangency and find the $b$ value so that the line passes through that point.






                          share|cite|improve this answer









                          $endgroup$















                            2












                            2








                            2





                            $begingroup$

                            Note that you like the line $y=x+b$ to be tangent to the parabola. The slope of this line is $ m=1.$ Thus the derivative of your parabola should be the same as the slope of the tangent line. Find the point of the tangency and find the $b$ value so that the line passes through that point.






                            share|cite|improve this answer









                            $endgroup$



                            Note that you like the line $y=x+b$ to be tangent to the parabola. The slope of this line is $ m=1.$ Thus the derivative of your parabola should be the same as the slope of the tangent line. Find the point of the tangency and find the $b$ value so that the line passes through that point.







                            share|cite|improve this answer












                            share|cite|improve this answer



                            share|cite|improve this answer










                            answered 5 hours ago









                            Mohammad Riazi-KermaniMohammad Riazi-Kermani

                            42.2k42061




                            42.2k42061




















                                swagbutton8 is a new contributor. Be nice, and check out our Code of Conduct.









                                draft saved

                                draft discarded


















                                swagbutton8 is a new contributor. Be nice, and check out our Code of Conduct.












                                swagbutton8 is a new contributor. Be nice, and check out our Code of Conduct.











                                swagbutton8 is a new contributor. Be nice, and check out our Code of Conduct.














                                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%2f3201227%2ffinding-a-tangent-line-to-a-parabola%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

                                Nidaros erkebispedøme

                                Birsay

                                Where did Arya get these scars? Unicorn Meta Zoo #1: Why another podcast? Announcing the arrival of Valued Associate #679: Cesar Manara Favourite questions and answers from the 1st quarter of 2019Why did Arya refuse to end it?Has the pronunciation of Arya Stark's name changed?Has Arya forgiven people?Why did Arya Stark lose her vision?Why can Arya still use the faces?Has the Narrow Sea become narrower?Does Arya Stark know how to make poisons outside of the House of Black and White?Why did Nymeria leave Arya?Why did Arya not kill the Lannister soldiers she encountered in the Riverlands?What is the current canonical age of Sansa, Bran and Arya Stark?