Maclaurin's series for $tan(x+x^2)$












1












$begingroup$


I would like to find the Maclaurin's series for $tan(x+x^2)$ stopped at $x_0^3$.



I tried with:
$$tan(x+x^2)=1+frac{1+2x_0}{cos^2(x_0+x_0^2)}x+....,$$ but it seems like the derivation gets more complicated. I was wondering if there was a simpler way to solve the Maclaurin series. I was thinking about putting $t=x+x^2$, but it looks like wrong (why?).



Update:



I know that MacLaurin's expansion for tan(x): $$T(x) = x + frac {1}{3}x^{3} + frac { 2 } { 15 } x ^ { 5 } + frac { 17 } { 315 } x ^ { 7 } + ldots$$ But according to Mathematica, there should be a $x^2$ for the MacLaurin series for $tan(x+x^2)$, which I couldn't understand.










share|cite|improve this question











$endgroup$












  • $begingroup$
    If all you care about is the series and not its derivation, why not use Mathematica? I doubt there is any special trick for this.
    $endgroup$
    – Hamed
    Jan 21 at 14:26












  • $begingroup$
    Could you show me an example? Do you mean substituting $x_0$ with 0 and solving the derivatives?
    $endgroup$
    – Kevin
    Jan 21 at 14:26










  • $begingroup$
    @Hamed Because it is part of a question of my past exams, and we are not allowed to use Mathematica.
    $endgroup$
    – Kevin
    Jan 21 at 14:28






  • 2




    $begingroup$
    Setting $t=x+x^2$ in the series for $tan{t}$ will work fine. Why wouldn't it?
    $endgroup$
    – saulspatz
    Jan 21 at 14:29










  • $begingroup$
    Apparently, the expansion is around an arbitrary point $x_0$ not zero.
    $endgroup$
    – Hamed
    Jan 21 at 14:33
















1












$begingroup$


I would like to find the Maclaurin's series for $tan(x+x^2)$ stopped at $x_0^3$.



I tried with:
$$tan(x+x^2)=1+frac{1+2x_0}{cos^2(x_0+x_0^2)}x+....,$$ but it seems like the derivation gets more complicated. I was wondering if there was a simpler way to solve the Maclaurin series. I was thinking about putting $t=x+x^2$, but it looks like wrong (why?).



Update:



I know that MacLaurin's expansion for tan(x): $$T(x) = x + frac {1}{3}x^{3} + frac { 2 } { 15 } x ^ { 5 } + frac { 17 } { 315 } x ^ { 7 } + ldots$$ But according to Mathematica, there should be a $x^2$ for the MacLaurin series for $tan(x+x^2)$, which I couldn't understand.










share|cite|improve this question











$endgroup$












  • $begingroup$
    If all you care about is the series and not its derivation, why not use Mathematica? I doubt there is any special trick for this.
    $endgroup$
    – Hamed
    Jan 21 at 14:26












  • $begingroup$
    Could you show me an example? Do you mean substituting $x_0$ with 0 and solving the derivatives?
    $endgroup$
    – Kevin
    Jan 21 at 14:26










  • $begingroup$
    @Hamed Because it is part of a question of my past exams, and we are not allowed to use Mathematica.
    $endgroup$
    – Kevin
    Jan 21 at 14:28






  • 2




    $begingroup$
    Setting $t=x+x^2$ in the series for $tan{t}$ will work fine. Why wouldn't it?
    $endgroup$
    – saulspatz
    Jan 21 at 14:29










  • $begingroup$
    Apparently, the expansion is around an arbitrary point $x_0$ not zero.
    $endgroup$
    – Hamed
    Jan 21 at 14:33














1












1








1





$begingroup$


I would like to find the Maclaurin's series for $tan(x+x^2)$ stopped at $x_0^3$.



I tried with:
$$tan(x+x^2)=1+frac{1+2x_0}{cos^2(x_0+x_0^2)}x+....,$$ but it seems like the derivation gets more complicated. I was wondering if there was a simpler way to solve the Maclaurin series. I was thinking about putting $t=x+x^2$, but it looks like wrong (why?).



Update:



I know that MacLaurin's expansion for tan(x): $$T(x) = x + frac {1}{3}x^{3} + frac { 2 } { 15 } x ^ { 5 } + frac { 17 } { 315 } x ^ { 7 } + ldots$$ But according to Mathematica, there should be a $x^2$ for the MacLaurin series for $tan(x+x^2)$, which I couldn't understand.










share|cite|improve this question











$endgroup$




I would like to find the Maclaurin's series for $tan(x+x^2)$ stopped at $x_0^3$.



I tried with:
$$tan(x+x^2)=1+frac{1+2x_0}{cos^2(x_0+x_0^2)}x+....,$$ but it seems like the derivation gets more complicated. I was wondering if there was a simpler way to solve the Maclaurin series. I was thinking about putting $t=x+x^2$, but it looks like wrong (why?).



Update:



I know that MacLaurin's expansion for tan(x): $$T(x) = x + frac {1}{3}x^{3} + frac { 2 } { 15 } x ^ { 5 } + frac { 17 } { 315 } x ^ { 7 } + ldots$$ But according to Mathematica, there should be a $x^2$ for the MacLaurin series for $tan(x+x^2)$, which I couldn't understand.







calculus derivatives taylor-expansion






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 21 at 14:53







Kevin

















asked Jan 21 at 14:18









KevinKevin

16211




16211












  • $begingroup$
    If all you care about is the series and not its derivation, why not use Mathematica? I doubt there is any special trick for this.
    $endgroup$
    – Hamed
    Jan 21 at 14:26












  • $begingroup$
    Could you show me an example? Do you mean substituting $x_0$ with 0 and solving the derivatives?
    $endgroup$
    – Kevin
    Jan 21 at 14:26










  • $begingroup$
    @Hamed Because it is part of a question of my past exams, and we are not allowed to use Mathematica.
    $endgroup$
    – Kevin
    Jan 21 at 14:28






  • 2




    $begingroup$
    Setting $t=x+x^2$ in the series for $tan{t}$ will work fine. Why wouldn't it?
    $endgroup$
    – saulspatz
    Jan 21 at 14:29










  • $begingroup$
    Apparently, the expansion is around an arbitrary point $x_0$ not zero.
    $endgroup$
    – Hamed
    Jan 21 at 14:33


















  • $begingroup$
    If all you care about is the series and not its derivation, why not use Mathematica? I doubt there is any special trick for this.
    $endgroup$
    – Hamed
    Jan 21 at 14:26












  • $begingroup$
    Could you show me an example? Do you mean substituting $x_0$ with 0 and solving the derivatives?
    $endgroup$
    – Kevin
    Jan 21 at 14:26










  • $begingroup$
    @Hamed Because it is part of a question of my past exams, and we are not allowed to use Mathematica.
    $endgroup$
    – Kevin
    Jan 21 at 14:28






  • 2




    $begingroup$
    Setting $t=x+x^2$ in the series for $tan{t}$ will work fine. Why wouldn't it?
    $endgroup$
    – saulspatz
    Jan 21 at 14:29










  • $begingroup$
    Apparently, the expansion is around an arbitrary point $x_0$ not zero.
    $endgroup$
    – Hamed
    Jan 21 at 14:33
















$begingroup$
If all you care about is the series and not its derivation, why not use Mathematica? I doubt there is any special trick for this.
$endgroup$
– Hamed
Jan 21 at 14:26






$begingroup$
If all you care about is the series and not its derivation, why not use Mathematica? I doubt there is any special trick for this.
$endgroup$
– Hamed
Jan 21 at 14:26














$begingroup$
Could you show me an example? Do you mean substituting $x_0$ with 0 and solving the derivatives?
$endgroup$
– Kevin
Jan 21 at 14:26




$begingroup$
Could you show me an example? Do you mean substituting $x_0$ with 0 and solving the derivatives?
$endgroup$
– Kevin
Jan 21 at 14:26












$begingroup$
@Hamed Because it is part of a question of my past exams, and we are not allowed to use Mathematica.
$endgroup$
– Kevin
Jan 21 at 14:28




$begingroup$
@Hamed Because it is part of a question of my past exams, and we are not allowed to use Mathematica.
$endgroup$
– Kevin
Jan 21 at 14:28




2




2




$begingroup$
Setting $t=x+x^2$ in the series for $tan{t}$ will work fine. Why wouldn't it?
$endgroup$
– saulspatz
Jan 21 at 14:29




$begingroup$
Setting $t=x+x^2$ in the series for $tan{t}$ will work fine. Why wouldn't it?
$endgroup$
– saulspatz
Jan 21 at 14:29












$begingroup$
Apparently, the expansion is around an arbitrary point $x_0$ not zero.
$endgroup$
– Hamed
Jan 21 at 14:33




$begingroup$
Apparently, the expansion is around an arbitrary point $x_0$ not zero.
$endgroup$
– Hamed
Jan 21 at 14:33










1 Answer
1






active

oldest

votes


















1












$begingroup$

Just substitute $x+x^2$ for $x$ in your formula of $T(x):$
$$T(x+x^2)=(x+x^2)+frac13(x+x^2)^3+cdots$$



Now you just have to expand and rearrange the terms. Since you only need powers up through $x^3$, there no need to be concerned with the higher-degree terms in $T(x)$






share|cite|improve this answer









$endgroup$













  • $begingroup$
    Now I get it. Apparently, I had a lot of confusion in my mind. Thank you!
    $endgroup$
    – Kevin
    Jan 21 at 15:09











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%2f3081921%2fmaclaurins-series-for-tanxx2%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









1












$begingroup$

Just substitute $x+x^2$ for $x$ in your formula of $T(x):$
$$T(x+x^2)=(x+x^2)+frac13(x+x^2)^3+cdots$$



Now you just have to expand and rearrange the terms. Since you only need powers up through $x^3$, there no need to be concerned with the higher-degree terms in $T(x)$






share|cite|improve this answer









$endgroup$













  • $begingroup$
    Now I get it. Apparently, I had a lot of confusion in my mind. Thank you!
    $endgroup$
    – Kevin
    Jan 21 at 15:09
















1












$begingroup$

Just substitute $x+x^2$ for $x$ in your formula of $T(x):$
$$T(x+x^2)=(x+x^2)+frac13(x+x^2)^3+cdots$$



Now you just have to expand and rearrange the terms. Since you only need powers up through $x^3$, there no need to be concerned with the higher-degree terms in $T(x)$






share|cite|improve this answer









$endgroup$













  • $begingroup$
    Now I get it. Apparently, I had a lot of confusion in my mind. Thank you!
    $endgroup$
    – Kevin
    Jan 21 at 15:09














1












1








1





$begingroup$

Just substitute $x+x^2$ for $x$ in your formula of $T(x):$
$$T(x+x^2)=(x+x^2)+frac13(x+x^2)^3+cdots$$



Now you just have to expand and rearrange the terms. Since you only need powers up through $x^3$, there no need to be concerned with the higher-degree terms in $T(x)$






share|cite|improve this answer









$endgroup$



Just substitute $x+x^2$ for $x$ in your formula of $T(x):$
$$T(x+x^2)=(x+x^2)+frac13(x+x^2)^3+cdots$$



Now you just have to expand and rearrange the terms. Since you only need powers up through $x^3$, there no need to be concerned with the higher-degree terms in $T(x)$







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered Jan 21 at 14:58









saulspatzsaulspatz

16.3k31332




16.3k31332












  • $begingroup$
    Now I get it. Apparently, I had a lot of confusion in my mind. Thank you!
    $endgroup$
    – Kevin
    Jan 21 at 15:09


















  • $begingroup$
    Now I get it. Apparently, I had a lot of confusion in my mind. Thank you!
    $endgroup$
    – Kevin
    Jan 21 at 15:09
















$begingroup$
Now I get it. Apparently, I had a lot of confusion in my mind. Thank you!
$endgroup$
– Kevin
Jan 21 at 15:09




$begingroup$
Now I get it. Apparently, I had a lot of confusion in my mind. Thank you!
$endgroup$
– Kevin
Jan 21 at 15:09


















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%2f3081921%2fmaclaurins-series-for-tanxx2%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

Can a sorcerer learn a 5th-level spell early by creating spell slots using the Font of Magic feature?

ts Property 'filter' does not exist on type '{}'

mat-slide-toggle shouldn't change it's state when I click cancel in confirmation window