Draw $r ≤ 3 + 2sin (theta)$












2












$begingroup$


Currently I'm stuck at this fairly easy task. All I have to do is sketch the region $r le 3+2sin theta$. My guess would be that the circle has the origin $(0,3)$ with $r = 2$, as I use the formula $y = b + r sin theta$. But that's completely wrong.



EDIT: I am interesting in the right procedure for drawing a region like this, not the actual plot itself. This was a question for a previous test without the use of calculators.










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    That equation does not define a circle. Why do you say it is a circle?
    $endgroup$
    – kccu
    Jan 23 at 21:32










  • $begingroup$
    That curve is not a circle (or rather, that region is not a disc).
    $endgroup$
    – Brian Tung
    Jan 23 at 21:32






  • 1




    $begingroup$
    If you're stuck, plot some points for various values of $theta$ and see if you notice anything
    $endgroup$
    – pwerth
    Jan 23 at 21:32










  • $begingroup$
    Oh sorry! I meant region instead of circle. I have plotted with desmos several different sin (θ) and also cos (θ), but I can't see a pattern. Only that sin (θ) is shifted upwards with origin (0,1) and cos (θ) to the right at (1,0).
    $endgroup$
    – d saline
    Jan 23 at 21:42










  • $begingroup$
    Desmos is a good tool to get an idea about the shape of a curve.
    $endgroup$
    – Math Lover
    Jan 23 at 21:48
















2












$begingroup$


Currently I'm stuck at this fairly easy task. All I have to do is sketch the region $r le 3+2sin theta$. My guess would be that the circle has the origin $(0,3)$ with $r = 2$, as I use the formula $y = b + r sin theta$. But that's completely wrong.



EDIT: I am interesting in the right procedure for drawing a region like this, not the actual plot itself. This was a question for a previous test without the use of calculators.










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    That equation does not define a circle. Why do you say it is a circle?
    $endgroup$
    – kccu
    Jan 23 at 21:32










  • $begingroup$
    That curve is not a circle (or rather, that region is not a disc).
    $endgroup$
    – Brian Tung
    Jan 23 at 21:32






  • 1




    $begingroup$
    If you're stuck, plot some points for various values of $theta$ and see if you notice anything
    $endgroup$
    – pwerth
    Jan 23 at 21:32










  • $begingroup$
    Oh sorry! I meant region instead of circle. I have plotted with desmos several different sin (θ) and also cos (θ), but I can't see a pattern. Only that sin (θ) is shifted upwards with origin (0,1) and cos (θ) to the right at (1,0).
    $endgroup$
    – d saline
    Jan 23 at 21:42










  • $begingroup$
    Desmos is a good tool to get an idea about the shape of a curve.
    $endgroup$
    – Math Lover
    Jan 23 at 21:48














2












2








2





$begingroup$


Currently I'm stuck at this fairly easy task. All I have to do is sketch the region $r le 3+2sin theta$. My guess would be that the circle has the origin $(0,3)$ with $r = 2$, as I use the formula $y = b + r sin theta$. But that's completely wrong.



EDIT: I am interesting in the right procedure for drawing a region like this, not the actual plot itself. This was a question for a previous test without the use of calculators.










share|cite|improve this question











$endgroup$




Currently I'm stuck at this fairly easy task. All I have to do is sketch the region $r le 3+2sin theta$. My guess would be that the circle has the origin $(0,3)$ with $r = 2$, as I use the formula $y = b + r sin theta$. But that's completely wrong.



EDIT: I am interesting in the right procedure for drawing a region like this, not the actual plot itself. This was a question for a previous test without the use of calculators.







calculus multivariable-calculus parametric parametrization






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 24 at 8:43







d saline

















asked Jan 23 at 21:27









d salined saline

162




162








  • 1




    $begingroup$
    That equation does not define a circle. Why do you say it is a circle?
    $endgroup$
    – kccu
    Jan 23 at 21:32










  • $begingroup$
    That curve is not a circle (or rather, that region is not a disc).
    $endgroup$
    – Brian Tung
    Jan 23 at 21:32






  • 1




    $begingroup$
    If you're stuck, plot some points for various values of $theta$ and see if you notice anything
    $endgroup$
    – pwerth
    Jan 23 at 21:32










  • $begingroup$
    Oh sorry! I meant region instead of circle. I have plotted with desmos several different sin (θ) and also cos (θ), but I can't see a pattern. Only that sin (θ) is shifted upwards with origin (0,1) and cos (θ) to the right at (1,0).
    $endgroup$
    – d saline
    Jan 23 at 21:42










  • $begingroup$
    Desmos is a good tool to get an idea about the shape of a curve.
    $endgroup$
    – Math Lover
    Jan 23 at 21:48














  • 1




    $begingroup$
    That equation does not define a circle. Why do you say it is a circle?
    $endgroup$
    – kccu
    Jan 23 at 21:32










  • $begingroup$
    That curve is not a circle (or rather, that region is not a disc).
    $endgroup$
    – Brian Tung
    Jan 23 at 21:32






  • 1




    $begingroup$
    If you're stuck, plot some points for various values of $theta$ and see if you notice anything
    $endgroup$
    – pwerth
    Jan 23 at 21:32










  • $begingroup$
    Oh sorry! I meant region instead of circle. I have plotted with desmos several different sin (θ) and also cos (θ), but I can't see a pattern. Only that sin (θ) is shifted upwards with origin (0,1) and cos (θ) to the right at (1,0).
    $endgroup$
    – d saline
    Jan 23 at 21:42










  • $begingroup$
    Desmos is a good tool to get an idea about the shape of a curve.
    $endgroup$
    – Math Lover
    Jan 23 at 21:48








1




1




$begingroup$
That equation does not define a circle. Why do you say it is a circle?
$endgroup$
– kccu
Jan 23 at 21:32




$begingroup$
That equation does not define a circle. Why do you say it is a circle?
$endgroup$
– kccu
Jan 23 at 21:32












$begingroup$
That curve is not a circle (or rather, that region is not a disc).
$endgroup$
– Brian Tung
Jan 23 at 21:32




$begingroup$
That curve is not a circle (or rather, that region is not a disc).
$endgroup$
– Brian Tung
Jan 23 at 21:32




1




1




$begingroup$
If you're stuck, plot some points for various values of $theta$ and see if you notice anything
$endgroup$
– pwerth
Jan 23 at 21:32




$begingroup$
If you're stuck, plot some points for various values of $theta$ and see if you notice anything
$endgroup$
– pwerth
Jan 23 at 21:32












$begingroup$
Oh sorry! I meant region instead of circle. I have plotted with desmos several different sin (θ) and also cos (θ), but I can't see a pattern. Only that sin (θ) is shifted upwards with origin (0,1) and cos (θ) to the right at (1,0).
$endgroup$
– d saline
Jan 23 at 21:42




$begingroup$
Oh sorry! I meant region instead of circle. I have plotted with desmos several different sin (θ) and also cos (θ), but I can't see a pattern. Only that sin (θ) is shifted upwards with origin (0,1) and cos (θ) to the right at (1,0).
$endgroup$
– d saline
Jan 23 at 21:42












$begingroup$
Desmos is a good tool to get an idea about the shape of a curve.
$endgroup$
– Math Lover
Jan 23 at 21:48




$begingroup$
Desmos is a good tool to get an idea about the shape of a curve.
$endgroup$
– Math Lover
Jan 23 at 21:48










2 Answers
2






active

oldest

votes


















5












$begingroup$

This equation is describing a limacon.



You mention that you have to sketch a circle, but it's not a circle. You can find the drawing corresponding to the equation here.



$r=3+2sin theta$ is an equation that require to use polar coordinates to draw the graph. Be sure to be familiar with it.



Pay attention, in your title you are using "=" but "≤" in your question. "=" will be a line whereas "≤" will be the surface inside that line.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Thanks, I have been sloppy with the sign and changed it in the title. That's probably a better way of frasing my question: I don't know ''how'' to plot r ≤ 3+2sin (θ) using polar coordinates. I know that x = rcos (θ), y = rsin (θ), I have tried squaring the term, still can't draw the region.
    $endgroup$
    – d saline
    Jan 24 at 8:41



















4












$begingroup$

Sometimes a picture is worth 1000 words:



enter image description here



If you want to work "by hand," you can make a traditional (rectilinear) plots of $r$, $x$ and $y$ (actually, you only need $x$ and $y$), then sample pairs of coordinates at different $theta$s and transfer them to your polar graph.



enter image description here






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Thank you, I see I didn't ask my question properly. I know what the region looks like, I just don't know how to draw it by hand without plotting various values of phi.
    $endgroup$
    – d saline
    Jan 24 at 8:36










  • $begingroup$
    I don't think anyone knows how to draw it by hand without plotting various values of $phi$.
    $endgroup$
    – David G. Stork
    Jan 24 at 18:55











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%2f3085103%2fdraw-r-%25e2%2589%25a4-3-2-sin-theta%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









5












$begingroup$

This equation is describing a limacon.



You mention that you have to sketch a circle, but it's not a circle. You can find the drawing corresponding to the equation here.



$r=3+2sin theta$ is an equation that require to use polar coordinates to draw the graph. Be sure to be familiar with it.



Pay attention, in your title you are using "=" but "≤" in your question. "=" will be a line whereas "≤" will be the surface inside that line.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Thanks, I have been sloppy with the sign and changed it in the title. That's probably a better way of frasing my question: I don't know ''how'' to plot r ≤ 3+2sin (θ) using polar coordinates. I know that x = rcos (θ), y = rsin (θ), I have tried squaring the term, still can't draw the region.
    $endgroup$
    – d saline
    Jan 24 at 8:41
















5












$begingroup$

This equation is describing a limacon.



You mention that you have to sketch a circle, but it's not a circle. You can find the drawing corresponding to the equation here.



$r=3+2sin theta$ is an equation that require to use polar coordinates to draw the graph. Be sure to be familiar with it.



Pay attention, in your title you are using "=" but "≤" in your question. "=" will be a line whereas "≤" will be the surface inside that line.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Thanks, I have been sloppy with the sign and changed it in the title. That's probably a better way of frasing my question: I don't know ''how'' to plot r ≤ 3+2sin (θ) using polar coordinates. I know that x = rcos (θ), y = rsin (θ), I have tried squaring the term, still can't draw the region.
    $endgroup$
    – d saline
    Jan 24 at 8:41














5












5








5





$begingroup$

This equation is describing a limacon.



You mention that you have to sketch a circle, but it's not a circle. You can find the drawing corresponding to the equation here.



$r=3+2sin theta$ is an equation that require to use polar coordinates to draw the graph. Be sure to be familiar with it.



Pay attention, in your title you are using "=" but "≤" in your question. "=" will be a line whereas "≤" will be the surface inside that line.






share|cite|improve this answer











$endgroup$



This equation is describing a limacon.



You mention that you have to sketch a circle, but it's not a circle. You can find the drawing corresponding to the equation here.



$r=3+2sin theta$ is an equation that require to use polar coordinates to draw the graph. Be sure to be familiar with it.



Pay attention, in your title you are using "=" but "≤" in your question. "=" will be a line whereas "≤" will be the surface inside that line.







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Jan 23 at 21:48









gt6989b

34.9k22557




34.9k22557










answered Jan 23 at 21:37









Vincent PerezVincent Perez

713




713












  • $begingroup$
    Thanks, I have been sloppy with the sign and changed it in the title. That's probably a better way of frasing my question: I don't know ''how'' to plot r ≤ 3+2sin (θ) using polar coordinates. I know that x = rcos (θ), y = rsin (θ), I have tried squaring the term, still can't draw the region.
    $endgroup$
    – d saline
    Jan 24 at 8:41


















  • $begingroup$
    Thanks, I have been sloppy with the sign and changed it in the title. That's probably a better way of frasing my question: I don't know ''how'' to plot r ≤ 3+2sin (θ) using polar coordinates. I know that x = rcos (θ), y = rsin (θ), I have tried squaring the term, still can't draw the region.
    $endgroup$
    – d saline
    Jan 24 at 8:41
















$begingroup$
Thanks, I have been sloppy with the sign and changed it in the title. That's probably a better way of frasing my question: I don't know ''how'' to plot r ≤ 3+2sin (θ) using polar coordinates. I know that x = rcos (θ), y = rsin (θ), I have tried squaring the term, still can't draw the region.
$endgroup$
– d saline
Jan 24 at 8:41




$begingroup$
Thanks, I have been sloppy with the sign and changed it in the title. That's probably a better way of frasing my question: I don't know ''how'' to plot r ≤ 3+2sin (θ) using polar coordinates. I know that x = rcos (θ), y = rsin (θ), I have tried squaring the term, still can't draw the region.
$endgroup$
– d saline
Jan 24 at 8:41











4












$begingroup$

Sometimes a picture is worth 1000 words:



enter image description here



If you want to work "by hand," you can make a traditional (rectilinear) plots of $r$, $x$ and $y$ (actually, you only need $x$ and $y$), then sample pairs of coordinates at different $theta$s and transfer them to your polar graph.



enter image description here






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Thank you, I see I didn't ask my question properly. I know what the region looks like, I just don't know how to draw it by hand without plotting various values of phi.
    $endgroup$
    – d saline
    Jan 24 at 8:36










  • $begingroup$
    I don't think anyone knows how to draw it by hand without plotting various values of $phi$.
    $endgroup$
    – David G. Stork
    Jan 24 at 18:55
















4












$begingroup$

Sometimes a picture is worth 1000 words:



enter image description here



If you want to work "by hand," you can make a traditional (rectilinear) plots of $r$, $x$ and $y$ (actually, you only need $x$ and $y$), then sample pairs of coordinates at different $theta$s and transfer them to your polar graph.



enter image description here






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Thank you, I see I didn't ask my question properly. I know what the region looks like, I just don't know how to draw it by hand without plotting various values of phi.
    $endgroup$
    – d saline
    Jan 24 at 8:36










  • $begingroup$
    I don't think anyone knows how to draw it by hand without plotting various values of $phi$.
    $endgroup$
    – David G. Stork
    Jan 24 at 18:55














4












4








4





$begingroup$

Sometimes a picture is worth 1000 words:



enter image description here



If you want to work "by hand," you can make a traditional (rectilinear) plots of $r$, $x$ and $y$ (actually, you only need $x$ and $y$), then sample pairs of coordinates at different $theta$s and transfer them to your polar graph.



enter image description here






share|cite|improve this answer











$endgroup$



Sometimes a picture is worth 1000 words:



enter image description here



If you want to work "by hand," you can make a traditional (rectilinear) plots of $r$, $x$ and $y$ (actually, you only need $x$ and $y$), then sample pairs of coordinates at different $theta$s and transfer them to your polar graph.



enter image description here







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Jan 23 at 22:10

























answered Jan 23 at 21:45









David G. StorkDavid G. Stork

11.1k41432




11.1k41432












  • $begingroup$
    Thank you, I see I didn't ask my question properly. I know what the region looks like, I just don't know how to draw it by hand without plotting various values of phi.
    $endgroup$
    – d saline
    Jan 24 at 8:36










  • $begingroup$
    I don't think anyone knows how to draw it by hand without plotting various values of $phi$.
    $endgroup$
    – David G. Stork
    Jan 24 at 18:55


















  • $begingroup$
    Thank you, I see I didn't ask my question properly. I know what the region looks like, I just don't know how to draw it by hand without plotting various values of phi.
    $endgroup$
    – d saline
    Jan 24 at 8:36










  • $begingroup$
    I don't think anyone knows how to draw it by hand without plotting various values of $phi$.
    $endgroup$
    – David G. Stork
    Jan 24 at 18:55
















$begingroup$
Thank you, I see I didn't ask my question properly. I know what the region looks like, I just don't know how to draw it by hand without plotting various values of phi.
$endgroup$
– d saline
Jan 24 at 8:36




$begingroup$
Thank you, I see I didn't ask my question properly. I know what the region looks like, I just don't know how to draw it by hand without plotting various values of phi.
$endgroup$
– d saline
Jan 24 at 8:36












$begingroup$
I don't think anyone knows how to draw it by hand without plotting various values of $phi$.
$endgroup$
– David G. Stork
Jan 24 at 18:55




$begingroup$
I don't think anyone knows how to draw it by hand without plotting various values of $phi$.
$endgroup$
– David G. Stork
Jan 24 at 18:55


















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%2f3085103%2fdraw-r-%25e2%2589%25a4-3-2-sin-theta%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

MongoDB - Not Authorized To Execute Command

How to fix TextFormField cause rebuild widget in Flutter

in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith