Smallest integer power for an inequality to hold
$begingroup$
so I have this inequality:
Given integers $m, kgeq1$.
$$2^{m/k} > frac{3}{2}$$
I'm interested in finding the smallest integer power $m$, as a function of $k$, that will make this inequality hold true.
I've made a few calculations and came up with $m$ as:
$$m(k) = [ 6k/10 + 0.5 ] - [k/70]$$
I'm almost certain that this $m$, for any given $k$, will satisfy the inequality. I believe it is the smallest integer (I don't know how to prove it, a proof will be appreciated!), but I wonder if there's a way to find another m that's a lot simpler... or maybe a way to simplify the m I found so I can use it in power additions and other things.
Or in general, is there a way/technique for such problems on how to find the smallest integer power?
Thank you for your time!
algebra-precalculus inequality exponentiation integers
$endgroup$
add a comment |
$begingroup$
so I have this inequality:
Given integers $m, kgeq1$.
$$2^{m/k} > frac{3}{2}$$
I'm interested in finding the smallest integer power $m$, as a function of $k$, that will make this inequality hold true.
I've made a few calculations and came up with $m$ as:
$$m(k) = [ 6k/10 + 0.5 ] - [k/70]$$
I'm almost certain that this $m$, for any given $k$, will satisfy the inequality. I believe it is the smallest integer (I don't know how to prove it, a proof will be appreciated!), but I wonder if there's a way to find another m that's a lot simpler... or maybe a way to simplify the m I found so I can use it in power additions and other things.
Or in general, is there a way/technique for such problems on how to find the smallest integer power?
Thank you for your time!
algebra-precalculus inequality exponentiation integers
$endgroup$
add a comment |
$begingroup$
so I have this inequality:
Given integers $m, kgeq1$.
$$2^{m/k} > frac{3}{2}$$
I'm interested in finding the smallest integer power $m$, as a function of $k$, that will make this inequality hold true.
I've made a few calculations and came up with $m$ as:
$$m(k) = [ 6k/10 + 0.5 ] - [k/70]$$
I'm almost certain that this $m$, for any given $k$, will satisfy the inequality. I believe it is the smallest integer (I don't know how to prove it, a proof will be appreciated!), but I wonder if there's a way to find another m that's a lot simpler... or maybe a way to simplify the m I found so I can use it in power additions and other things.
Or in general, is there a way/technique for such problems on how to find the smallest integer power?
Thank you for your time!
algebra-precalculus inequality exponentiation integers
$endgroup$
so I have this inequality:
Given integers $m, kgeq1$.
$$2^{m/k} > frac{3}{2}$$
I'm interested in finding the smallest integer power $m$, as a function of $k$, that will make this inequality hold true.
I've made a few calculations and came up with $m$ as:
$$m(k) = [ 6k/10 + 0.5 ] - [k/70]$$
I'm almost certain that this $m$, for any given $k$, will satisfy the inequality. I believe it is the smallest integer (I don't know how to prove it, a proof will be appreciated!), but I wonder if there's a way to find another m that's a lot simpler... or maybe a way to simplify the m I found so I can use it in power additions and other things.
Or in general, is there a way/technique for such problems on how to find the smallest integer power?
Thank you for your time!
algebra-precalculus inequality exponentiation integers
algebra-precalculus inequality exponentiation integers
edited Dec 2 '18 at 22:21
Servaes
23.3k33893
23.3k33893
asked Dec 2 '18 at 22:06
Buk LauBuk Lau
1878
1878
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
Given a positive integer $k$ you want to find the least positive integer $m$ such that $2^{m/k}>frac{3}{2}$, or equivalently
$$frac{m}{k}>frac{log(frac{3}{2})}{log2}=frac{log3-log2}{log2}=frac{log3}{log2}-1,$$
or equivalently $m>kcdotleft(frac{log3}{log2}-1right)$. The latter is a constant; an online calculator tells me that
$$frac{log3}{log2}-1approx0.5849625,$$
so $m=lceil0.5849625ldotstimes krceil$.
$endgroup$
$begingroup$
Thank you for your quick answer! So m should be [k*0.5849625 + 0.5] correct?
$endgroup$
– Buk Lau
Dec 2 '18 at 22:12
add a comment |
$begingroup$
HINT
We have that since $log$ function is strictly increasing
$$2^{m/k} > 3/2 iff log (2^{m/k}) > log (3/2)$$
$endgroup$
add a comment |
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
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3023280%2fsmallest-integer-power-for-an-inequality-to-hold%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
$begingroup$
Given a positive integer $k$ you want to find the least positive integer $m$ such that $2^{m/k}>frac{3}{2}$, or equivalently
$$frac{m}{k}>frac{log(frac{3}{2})}{log2}=frac{log3-log2}{log2}=frac{log3}{log2}-1,$$
or equivalently $m>kcdotleft(frac{log3}{log2}-1right)$. The latter is a constant; an online calculator tells me that
$$frac{log3}{log2}-1approx0.5849625,$$
so $m=lceil0.5849625ldotstimes krceil$.
$endgroup$
$begingroup$
Thank you for your quick answer! So m should be [k*0.5849625 + 0.5] correct?
$endgroup$
– Buk Lau
Dec 2 '18 at 22:12
add a comment |
$begingroup$
Given a positive integer $k$ you want to find the least positive integer $m$ such that $2^{m/k}>frac{3}{2}$, or equivalently
$$frac{m}{k}>frac{log(frac{3}{2})}{log2}=frac{log3-log2}{log2}=frac{log3}{log2}-1,$$
or equivalently $m>kcdotleft(frac{log3}{log2}-1right)$. The latter is a constant; an online calculator tells me that
$$frac{log3}{log2}-1approx0.5849625,$$
so $m=lceil0.5849625ldotstimes krceil$.
$endgroup$
$begingroup$
Thank you for your quick answer! So m should be [k*0.5849625 + 0.5] correct?
$endgroup$
– Buk Lau
Dec 2 '18 at 22:12
add a comment |
$begingroup$
Given a positive integer $k$ you want to find the least positive integer $m$ such that $2^{m/k}>frac{3}{2}$, or equivalently
$$frac{m}{k}>frac{log(frac{3}{2})}{log2}=frac{log3-log2}{log2}=frac{log3}{log2}-1,$$
or equivalently $m>kcdotleft(frac{log3}{log2}-1right)$. The latter is a constant; an online calculator tells me that
$$frac{log3}{log2}-1approx0.5849625,$$
so $m=lceil0.5849625ldotstimes krceil$.
$endgroup$
Given a positive integer $k$ you want to find the least positive integer $m$ such that $2^{m/k}>frac{3}{2}$, or equivalently
$$frac{m}{k}>frac{log(frac{3}{2})}{log2}=frac{log3-log2}{log2}=frac{log3}{log2}-1,$$
or equivalently $m>kcdotleft(frac{log3}{log2}-1right)$. The latter is a constant; an online calculator tells me that
$$frac{log3}{log2}-1approx0.5849625,$$
so $m=lceil0.5849625ldotstimes krceil$.
edited Dec 2 '18 at 22:13
answered Dec 2 '18 at 22:09
ServaesServaes
23.3k33893
23.3k33893
$begingroup$
Thank you for your quick answer! So m should be [k*0.5849625 + 0.5] correct?
$endgroup$
– Buk Lau
Dec 2 '18 at 22:12
add a comment |
$begingroup$
Thank you for your quick answer! So m should be [k*0.5849625 + 0.5] correct?
$endgroup$
– Buk Lau
Dec 2 '18 at 22:12
$begingroup$
Thank you for your quick answer! So m should be [k*0.5849625 + 0.5] correct?
$endgroup$
– Buk Lau
Dec 2 '18 at 22:12
$begingroup$
Thank you for your quick answer! So m should be [k*0.5849625 + 0.5] correct?
$endgroup$
– Buk Lau
Dec 2 '18 at 22:12
add a comment |
$begingroup$
HINT
We have that since $log$ function is strictly increasing
$$2^{m/k} > 3/2 iff log (2^{m/k}) > log (3/2)$$
$endgroup$
add a comment |
$begingroup$
HINT
We have that since $log$ function is strictly increasing
$$2^{m/k} > 3/2 iff log (2^{m/k}) > log (3/2)$$
$endgroup$
add a comment |
$begingroup$
HINT
We have that since $log$ function is strictly increasing
$$2^{m/k} > 3/2 iff log (2^{m/k}) > log (3/2)$$
$endgroup$
HINT
We have that since $log$ function is strictly increasing
$$2^{m/k} > 3/2 iff log (2^{m/k}) > log (3/2)$$
answered Dec 2 '18 at 22:08
gimusigimusi
92.8k84494
92.8k84494
add a comment |
add a comment |
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.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3023280%2fsmallest-integer-power-for-an-inequality-to-hold%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
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