let $f(x) = tan ^{-1}x, x in mathbb{R} $ .then choose the correct statement












0












$begingroup$


let $f(x) = tan ^{-1}x, x in mathbb{R} $ .then



choose the correct statement



$1.$ there exist a polynomial $p(x)$ satisfying $p(x)f'(x) =1$ for all $x$



$2.$$f^{(n)}(0) =0$ for all positive even integer $n$



$3.$ the sequence ${f^{(n)} (0) }$ is unbounded



$4.$$f^{(n)} (0) =0$ for all $n$



My attempt : if $ x =0$ ,then obviously $f(x) =0$ because $tan 0 =0$



from this i see option $2)$ and option $4)$ will correct



other option i don't know...



Any hints/solution will be apprecaited



thanks u










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    For $(2)$ and $(4)$, I think you misunderstood $f^{(n)}(0)$ as $(f(0))^n; f^{(n)}(0)$ means the $n^{th}$ derivative of $f$ at $x=0$.
    $endgroup$
    – Shubham Johri
    Dec 12 '18 at 20:45












  • $begingroup$
    thanks @ShubhamJohri...
    $endgroup$
    – jasmine
    Dec 12 '18 at 20:53
















0












$begingroup$


let $f(x) = tan ^{-1}x, x in mathbb{R} $ .then



choose the correct statement



$1.$ there exist a polynomial $p(x)$ satisfying $p(x)f'(x) =1$ for all $x$



$2.$$f^{(n)}(0) =0$ for all positive even integer $n$



$3.$ the sequence ${f^{(n)} (0) }$ is unbounded



$4.$$f^{(n)} (0) =0$ for all $n$



My attempt : if $ x =0$ ,then obviously $f(x) =0$ because $tan 0 =0$



from this i see option $2)$ and option $4)$ will correct



other option i don't know...



Any hints/solution will be apprecaited



thanks u










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    For $(2)$ and $(4)$, I think you misunderstood $f^{(n)}(0)$ as $(f(0))^n; f^{(n)}(0)$ means the $n^{th}$ derivative of $f$ at $x=0$.
    $endgroup$
    – Shubham Johri
    Dec 12 '18 at 20:45












  • $begingroup$
    thanks @ShubhamJohri...
    $endgroup$
    – jasmine
    Dec 12 '18 at 20:53














0












0








0





$begingroup$


let $f(x) = tan ^{-1}x, x in mathbb{R} $ .then



choose the correct statement



$1.$ there exist a polynomial $p(x)$ satisfying $p(x)f'(x) =1$ for all $x$



$2.$$f^{(n)}(0) =0$ for all positive even integer $n$



$3.$ the sequence ${f^{(n)} (0) }$ is unbounded



$4.$$f^{(n)} (0) =0$ for all $n$



My attempt : if $ x =0$ ,then obviously $f(x) =0$ because $tan 0 =0$



from this i see option $2)$ and option $4)$ will correct



other option i don't know...



Any hints/solution will be apprecaited



thanks u










share|cite|improve this question









$endgroup$




let $f(x) = tan ^{-1}x, x in mathbb{R} $ .then



choose the correct statement



$1.$ there exist a polynomial $p(x)$ satisfying $p(x)f'(x) =1$ for all $x$



$2.$$f^{(n)}(0) =0$ for all positive even integer $n$



$3.$ the sequence ${f^{(n)} (0) }$ is unbounded



$4.$$f^{(n)} (0) =0$ for all $n$



My attempt : if $ x =0$ ,then obviously $f(x) =0$ because $tan 0 =0$



from this i see option $2)$ and option $4)$ will correct



other option i don't know...



Any hints/solution will be apprecaited



thanks u







real-analysis






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 12 '18 at 19:51









jasminejasmine

1,791418




1,791418








  • 1




    $begingroup$
    For $(2)$ and $(4)$, I think you misunderstood $f^{(n)}(0)$ as $(f(0))^n; f^{(n)}(0)$ means the $n^{th}$ derivative of $f$ at $x=0$.
    $endgroup$
    – Shubham Johri
    Dec 12 '18 at 20:45












  • $begingroup$
    thanks @ShubhamJohri...
    $endgroup$
    – jasmine
    Dec 12 '18 at 20:53














  • 1




    $begingroup$
    For $(2)$ and $(4)$, I think you misunderstood $f^{(n)}(0)$ as $(f(0))^n; f^{(n)}(0)$ means the $n^{th}$ derivative of $f$ at $x=0$.
    $endgroup$
    – Shubham Johri
    Dec 12 '18 at 20:45












  • $begingroup$
    thanks @ShubhamJohri...
    $endgroup$
    – jasmine
    Dec 12 '18 at 20:53








1




1




$begingroup$
For $(2)$ and $(4)$, I think you misunderstood $f^{(n)}(0)$ as $(f(0))^n; f^{(n)}(0)$ means the $n^{th}$ derivative of $f$ at $x=0$.
$endgroup$
– Shubham Johri
Dec 12 '18 at 20:45






$begingroup$
For $(2)$ and $(4)$, I think you misunderstood $f^{(n)}(0)$ as $(f(0))^n; f^{(n)}(0)$ means the $n^{th}$ derivative of $f$ at $x=0$.
$endgroup$
– Shubham Johri
Dec 12 '18 at 20:45














$begingroup$
thanks @ShubhamJohri...
$endgroup$
– jasmine
Dec 12 '18 at 20:53




$begingroup$
thanks @ShubhamJohri...
$endgroup$
– jasmine
Dec 12 '18 at 20:53










1 Answer
1






active

oldest

votes


















2












$begingroup$

Yes to 1, viz. $p=1+x^2$. Yes to 2, because $f$, like $tan x$, is odd and infinitely differentiable. But 4 is false, viz. e.g. $n=1$. As for 3, note that $f=x-x^3/3+x^5/5-cdots$, so the odd derivaties at $0$ are $(-1)^n(2n)!$, so 3 is true.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    @J. G im not getting how option 3, 4 false can u elaborate more in detail ???
    $endgroup$
    – jasmine
    Dec 12 '18 at 20:02










  • $begingroup$
    @BarryCipra Sorry; I misread it as restricting to even $n$.
    $endgroup$
    – J.G.
    Dec 12 '18 at 20:05










  • $begingroup$
    THanks u @JG ..
    $endgroup$
    – jasmine
    Dec 12 '18 at 21:00











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%2f3037149%2flet-fx-tan-1x-x-in-mathbbr-then-choose-the-correct-statement%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









2












$begingroup$

Yes to 1, viz. $p=1+x^2$. Yes to 2, because $f$, like $tan x$, is odd and infinitely differentiable. But 4 is false, viz. e.g. $n=1$. As for 3, note that $f=x-x^3/3+x^5/5-cdots$, so the odd derivaties at $0$ are $(-1)^n(2n)!$, so 3 is true.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    @J. G im not getting how option 3, 4 false can u elaborate more in detail ???
    $endgroup$
    – jasmine
    Dec 12 '18 at 20:02










  • $begingroup$
    @BarryCipra Sorry; I misread it as restricting to even $n$.
    $endgroup$
    – J.G.
    Dec 12 '18 at 20:05










  • $begingroup$
    THanks u @JG ..
    $endgroup$
    – jasmine
    Dec 12 '18 at 21:00
















2












$begingroup$

Yes to 1, viz. $p=1+x^2$. Yes to 2, because $f$, like $tan x$, is odd and infinitely differentiable. But 4 is false, viz. e.g. $n=1$. As for 3, note that $f=x-x^3/3+x^5/5-cdots$, so the odd derivaties at $0$ are $(-1)^n(2n)!$, so 3 is true.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    @J. G im not getting how option 3, 4 false can u elaborate more in detail ???
    $endgroup$
    – jasmine
    Dec 12 '18 at 20:02










  • $begingroup$
    @BarryCipra Sorry; I misread it as restricting to even $n$.
    $endgroup$
    – J.G.
    Dec 12 '18 at 20:05










  • $begingroup$
    THanks u @JG ..
    $endgroup$
    – jasmine
    Dec 12 '18 at 21:00














2












2








2





$begingroup$

Yes to 1, viz. $p=1+x^2$. Yes to 2, because $f$, like $tan x$, is odd and infinitely differentiable. But 4 is false, viz. e.g. $n=1$. As for 3, note that $f=x-x^3/3+x^5/5-cdots$, so the odd derivaties at $0$ are $(-1)^n(2n)!$, so 3 is true.






share|cite|improve this answer











$endgroup$



Yes to 1, viz. $p=1+x^2$. Yes to 2, because $f$, like $tan x$, is odd and infinitely differentiable. But 4 is false, viz. e.g. $n=1$. As for 3, note that $f=x-x^3/3+x^5/5-cdots$, so the odd derivaties at $0$ are $(-1)^n(2n)!$, so 3 is true.







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Dec 12 '18 at 20:05

























answered Dec 12 '18 at 19:59









J.G.J.G.

28k22844




28k22844












  • $begingroup$
    @J. G im not getting how option 3, 4 false can u elaborate more in detail ???
    $endgroup$
    – jasmine
    Dec 12 '18 at 20:02










  • $begingroup$
    @BarryCipra Sorry; I misread it as restricting to even $n$.
    $endgroup$
    – J.G.
    Dec 12 '18 at 20:05










  • $begingroup$
    THanks u @JG ..
    $endgroup$
    – jasmine
    Dec 12 '18 at 21:00


















  • $begingroup$
    @J. G im not getting how option 3, 4 false can u elaborate more in detail ???
    $endgroup$
    – jasmine
    Dec 12 '18 at 20:02










  • $begingroup$
    @BarryCipra Sorry; I misread it as restricting to even $n$.
    $endgroup$
    – J.G.
    Dec 12 '18 at 20:05










  • $begingroup$
    THanks u @JG ..
    $endgroup$
    – jasmine
    Dec 12 '18 at 21:00
















$begingroup$
@J. G im not getting how option 3, 4 false can u elaborate more in detail ???
$endgroup$
– jasmine
Dec 12 '18 at 20:02




$begingroup$
@J. G im not getting how option 3, 4 false can u elaborate more in detail ???
$endgroup$
– jasmine
Dec 12 '18 at 20:02












$begingroup$
@BarryCipra Sorry; I misread it as restricting to even $n$.
$endgroup$
– J.G.
Dec 12 '18 at 20:05




$begingroup$
@BarryCipra Sorry; I misread it as restricting to even $n$.
$endgroup$
– J.G.
Dec 12 '18 at 20:05












$begingroup$
THanks u @JG ..
$endgroup$
– jasmine
Dec 12 '18 at 21:00




$begingroup$
THanks u @JG ..
$endgroup$
– jasmine
Dec 12 '18 at 21:00


















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%2f3037149%2flet-fx-tan-1x-x-in-mathbbr-then-choose-the-correct-statement%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

Plaza Victoria

In PowerPoint, is there a keyboard shortcut for bulleted / numbered list?

How to put 3 figures in Latex with 2 figures side by side and 1 below these side by side images but in...