Differential of iterative function
$begingroup$
I previously got great help with understanding that
$$C = -Afrac{frac{K1}{f1^2H}+2frac{K1K2}{f1^2f2H^2}+3frac{K1K2K3}{f1^3f3H^3}}{1+frac{K1}{f1^2H}+frac{K1K2}{f1^2f2H^2}+frac{K1K2K3}{f1^3f3H^3}}$$
always had a positive differential in H (differentiation of difficult function with unknown constants)
Now I wonder if we can generalize - the general next entry in the numerator would be
$$ifrac{K1K2...Ki}{f1^ifiH^i}$$ and the next entry in the denominator would be
$$frac{K1K2...Ki}{f1^ifiH^i}$$ - it seems also from actual numeric experimenttion that it is indeed true that the general differential is still positive - but can we prove that?
I should add that all K and f values are positive and H (proton concentration) is also positive. K values are true thermodynamic constants, and f values, activity coefficients are assumed fixed for each value of total buffer concentration (A) as a first approximation.
calculus
$endgroup$
add a comment |
$begingroup$
I previously got great help with understanding that
$$C = -Afrac{frac{K1}{f1^2H}+2frac{K1K2}{f1^2f2H^2}+3frac{K1K2K3}{f1^3f3H^3}}{1+frac{K1}{f1^2H}+frac{K1K2}{f1^2f2H^2}+frac{K1K2K3}{f1^3f3H^3}}$$
always had a positive differential in H (differentiation of difficult function with unknown constants)
Now I wonder if we can generalize - the general next entry in the numerator would be
$$ifrac{K1K2...Ki}{f1^ifiH^i}$$ and the next entry in the denominator would be
$$frac{K1K2...Ki}{f1^ifiH^i}$$ - it seems also from actual numeric experimenttion that it is indeed true that the general differential is still positive - but can we prove that?
I should add that all K and f values are positive and H (proton concentration) is also positive. K values are true thermodynamic constants, and f values, activity coefficients are assumed fixed for each value of total buffer concentration (A) as a first approximation.
calculus
$endgroup$
add a comment |
$begingroup$
I previously got great help with understanding that
$$C = -Afrac{frac{K1}{f1^2H}+2frac{K1K2}{f1^2f2H^2}+3frac{K1K2K3}{f1^3f3H^3}}{1+frac{K1}{f1^2H}+frac{K1K2}{f1^2f2H^2}+frac{K1K2K3}{f1^3f3H^3}}$$
always had a positive differential in H (differentiation of difficult function with unknown constants)
Now I wonder if we can generalize - the general next entry in the numerator would be
$$ifrac{K1K2...Ki}{f1^ifiH^i}$$ and the next entry in the denominator would be
$$frac{K1K2...Ki}{f1^ifiH^i}$$ - it seems also from actual numeric experimenttion that it is indeed true that the general differential is still positive - but can we prove that?
I should add that all K and f values are positive and H (proton concentration) is also positive. K values are true thermodynamic constants, and f values, activity coefficients are assumed fixed for each value of total buffer concentration (A) as a first approximation.
calculus
$endgroup$
I previously got great help with understanding that
$$C = -Afrac{frac{K1}{f1^2H}+2frac{K1K2}{f1^2f2H^2}+3frac{K1K2K3}{f1^3f3H^3}}{1+frac{K1}{f1^2H}+frac{K1K2}{f1^2f2H^2}+frac{K1K2K3}{f1^3f3H^3}}$$
always had a positive differential in H (differentiation of difficult function with unknown constants)
Now I wonder if we can generalize - the general next entry in the numerator would be
$$ifrac{K1K2...Ki}{f1^ifiH^i}$$ and the next entry in the denominator would be
$$frac{K1K2...Ki}{f1^ifiH^i}$$ - it seems also from actual numeric experimenttion that it is indeed true that the general differential is still positive - but can we prove that?
I should add that all K and f values are positive and H (proton concentration) is also positive. K values are true thermodynamic constants, and f values, activity coefficients are assumed fixed for each value of total buffer concentration (A) as a first approximation.
calculus
calculus
edited Jan 18 at 16:02
user37217
asked Jan 14 at 8:39
user37217user37217
12
12
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
This is not a proof.
Let $H=frac 1x$ and consider the function
$$f=frac{sum _{i=1}^n i, a_i, x^i}{1+sum _{i=1}^n a_i, x^i}$$ Compute the derivative to get
$$left(1+sum _{i=1}^n a_i, x^i right)^2, f'=left(sum _{i=1}^n i^2 a_i x^{i-1}right) left(1+sum _{i=1}^n a_i
x^iright)-left(sum _{i=1}^n i a_i x^{i-1}right)left( sum _{i=1}^n i a_i
x^iright)$$ The rhs is then a polynomial of degree $2(n-1)$ that is to say
$$text{rhs}=sum_{i=0}^{2(n-1)} b_i,x^i$$ in which the coefficients are all positive since all $a_i$'s are non negative. For example, using $n=10$, we should get
$$left(
begin{array}{cc}
i & b_i \
0 & a_1 \
1 & 4 a_2 \
2 & a_1 a_2+9 a_3 \
3 & 4 a_1 a_3+16 a_4 \
4 & a_2 a_3+9 a_1 a_4+25 a_5 \
5 & 4 a_2 a_4+16 a_1 a_5+36 a_6 \
6 & a_3 a_4+9 a_2 a_5+25 a_1 a_6+49 a_7 \
7 & 4 a_3 a_5+16 a_2 a_6+36 a_1 a_7+64 a_8 \
8 & a_4 a_5+9 a_3 a_6+25 a_2 a_7+49 a_1 a_8+81 a_9 \
9 & 4 a_4 a_6+16 a_3 a_7+36 a_2 a_8+64 a_1 a_9+100 a_{10} \
10 & a_5 a_6+9 a_4 a_7+25 a_3 a_8+49 a_2 a_9+81 a_1 a_{10} \
11 & 4 a_5 a_7+16 a_4 a_8+36 a_3 a_9+64 a_2 a_{10} \
12 & a_6 a_7+9 a_5 a_8+25 a_4 a_9+49 a_3 a_{10} \
13 & 4 a_6 a_8+16 a_5 a_9+36 a_4 a_{10} \
14 & a_7 a_8+9 a_6 a_9+25 a_5 a_{10} \
15 & 4 a_7 a_9+16 a_6 a_{10} \
16 & a_8 a_9+9 a_7 a_{10} \
17 & 4 a_8 a_{10} \
18 & a_9 a_{10}
end{array}
right)$$
$endgroup$
$begingroup$
Thanks a lot - but what is then the interpretation in regard tothe question of whether we caan know if thederivativeis positive?
$endgroup$
– user37217
Jan 26 at 8:06
$begingroup$
@user37217. You have sums of only positive terms.
$endgroup$
– Claude Leibovici
Jan 26 at 8:43
$begingroup$
Thanks a lot - so this is indeed a proof? - nice!!!
$endgroup$
– user37217
Jan 26 at 13:35
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%2f3072992%2fdifferential-of-iterative-function%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
$begingroup$
This is not a proof.
Let $H=frac 1x$ and consider the function
$$f=frac{sum _{i=1}^n i, a_i, x^i}{1+sum _{i=1}^n a_i, x^i}$$ Compute the derivative to get
$$left(1+sum _{i=1}^n a_i, x^i right)^2, f'=left(sum _{i=1}^n i^2 a_i x^{i-1}right) left(1+sum _{i=1}^n a_i
x^iright)-left(sum _{i=1}^n i a_i x^{i-1}right)left( sum _{i=1}^n i a_i
x^iright)$$ The rhs is then a polynomial of degree $2(n-1)$ that is to say
$$text{rhs}=sum_{i=0}^{2(n-1)} b_i,x^i$$ in which the coefficients are all positive since all $a_i$'s are non negative. For example, using $n=10$, we should get
$$left(
begin{array}{cc}
i & b_i \
0 & a_1 \
1 & 4 a_2 \
2 & a_1 a_2+9 a_3 \
3 & 4 a_1 a_3+16 a_4 \
4 & a_2 a_3+9 a_1 a_4+25 a_5 \
5 & 4 a_2 a_4+16 a_1 a_5+36 a_6 \
6 & a_3 a_4+9 a_2 a_5+25 a_1 a_6+49 a_7 \
7 & 4 a_3 a_5+16 a_2 a_6+36 a_1 a_7+64 a_8 \
8 & a_4 a_5+9 a_3 a_6+25 a_2 a_7+49 a_1 a_8+81 a_9 \
9 & 4 a_4 a_6+16 a_3 a_7+36 a_2 a_8+64 a_1 a_9+100 a_{10} \
10 & a_5 a_6+9 a_4 a_7+25 a_3 a_8+49 a_2 a_9+81 a_1 a_{10} \
11 & 4 a_5 a_7+16 a_4 a_8+36 a_3 a_9+64 a_2 a_{10} \
12 & a_6 a_7+9 a_5 a_8+25 a_4 a_9+49 a_3 a_{10} \
13 & 4 a_6 a_8+16 a_5 a_9+36 a_4 a_{10} \
14 & a_7 a_8+9 a_6 a_9+25 a_5 a_{10} \
15 & 4 a_7 a_9+16 a_6 a_{10} \
16 & a_8 a_9+9 a_7 a_{10} \
17 & 4 a_8 a_{10} \
18 & a_9 a_{10}
end{array}
right)$$
$endgroup$
$begingroup$
Thanks a lot - but what is then the interpretation in regard tothe question of whether we caan know if thederivativeis positive?
$endgroup$
– user37217
Jan 26 at 8:06
$begingroup$
@user37217. You have sums of only positive terms.
$endgroup$
– Claude Leibovici
Jan 26 at 8:43
$begingroup$
Thanks a lot - so this is indeed a proof? - nice!!!
$endgroup$
– user37217
Jan 26 at 13:35
add a comment |
$begingroup$
This is not a proof.
Let $H=frac 1x$ and consider the function
$$f=frac{sum _{i=1}^n i, a_i, x^i}{1+sum _{i=1}^n a_i, x^i}$$ Compute the derivative to get
$$left(1+sum _{i=1}^n a_i, x^i right)^2, f'=left(sum _{i=1}^n i^2 a_i x^{i-1}right) left(1+sum _{i=1}^n a_i
x^iright)-left(sum _{i=1}^n i a_i x^{i-1}right)left( sum _{i=1}^n i a_i
x^iright)$$ The rhs is then a polynomial of degree $2(n-1)$ that is to say
$$text{rhs}=sum_{i=0}^{2(n-1)} b_i,x^i$$ in which the coefficients are all positive since all $a_i$'s are non negative. For example, using $n=10$, we should get
$$left(
begin{array}{cc}
i & b_i \
0 & a_1 \
1 & 4 a_2 \
2 & a_1 a_2+9 a_3 \
3 & 4 a_1 a_3+16 a_4 \
4 & a_2 a_3+9 a_1 a_4+25 a_5 \
5 & 4 a_2 a_4+16 a_1 a_5+36 a_6 \
6 & a_3 a_4+9 a_2 a_5+25 a_1 a_6+49 a_7 \
7 & 4 a_3 a_5+16 a_2 a_6+36 a_1 a_7+64 a_8 \
8 & a_4 a_5+9 a_3 a_6+25 a_2 a_7+49 a_1 a_8+81 a_9 \
9 & 4 a_4 a_6+16 a_3 a_7+36 a_2 a_8+64 a_1 a_9+100 a_{10} \
10 & a_5 a_6+9 a_4 a_7+25 a_3 a_8+49 a_2 a_9+81 a_1 a_{10} \
11 & 4 a_5 a_7+16 a_4 a_8+36 a_3 a_9+64 a_2 a_{10} \
12 & a_6 a_7+9 a_5 a_8+25 a_4 a_9+49 a_3 a_{10} \
13 & 4 a_6 a_8+16 a_5 a_9+36 a_4 a_{10} \
14 & a_7 a_8+9 a_6 a_9+25 a_5 a_{10} \
15 & 4 a_7 a_9+16 a_6 a_{10} \
16 & a_8 a_9+9 a_7 a_{10} \
17 & 4 a_8 a_{10} \
18 & a_9 a_{10}
end{array}
right)$$
$endgroup$
$begingroup$
Thanks a lot - but what is then the interpretation in regard tothe question of whether we caan know if thederivativeis positive?
$endgroup$
– user37217
Jan 26 at 8:06
$begingroup$
@user37217. You have sums of only positive terms.
$endgroup$
– Claude Leibovici
Jan 26 at 8:43
$begingroup$
Thanks a lot - so this is indeed a proof? - nice!!!
$endgroup$
– user37217
Jan 26 at 13:35
add a comment |
$begingroup$
This is not a proof.
Let $H=frac 1x$ and consider the function
$$f=frac{sum _{i=1}^n i, a_i, x^i}{1+sum _{i=1}^n a_i, x^i}$$ Compute the derivative to get
$$left(1+sum _{i=1}^n a_i, x^i right)^2, f'=left(sum _{i=1}^n i^2 a_i x^{i-1}right) left(1+sum _{i=1}^n a_i
x^iright)-left(sum _{i=1}^n i a_i x^{i-1}right)left( sum _{i=1}^n i a_i
x^iright)$$ The rhs is then a polynomial of degree $2(n-1)$ that is to say
$$text{rhs}=sum_{i=0}^{2(n-1)} b_i,x^i$$ in which the coefficients are all positive since all $a_i$'s are non negative. For example, using $n=10$, we should get
$$left(
begin{array}{cc}
i & b_i \
0 & a_1 \
1 & 4 a_2 \
2 & a_1 a_2+9 a_3 \
3 & 4 a_1 a_3+16 a_4 \
4 & a_2 a_3+9 a_1 a_4+25 a_5 \
5 & 4 a_2 a_4+16 a_1 a_5+36 a_6 \
6 & a_3 a_4+9 a_2 a_5+25 a_1 a_6+49 a_7 \
7 & 4 a_3 a_5+16 a_2 a_6+36 a_1 a_7+64 a_8 \
8 & a_4 a_5+9 a_3 a_6+25 a_2 a_7+49 a_1 a_8+81 a_9 \
9 & 4 a_4 a_6+16 a_3 a_7+36 a_2 a_8+64 a_1 a_9+100 a_{10} \
10 & a_5 a_6+9 a_4 a_7+25 a_3 a_8+49 a_2 a_9+81 a_1 a_{10} \
11 & 4 a_5 a_7+16 a_4 a_8+36 a_3 a_9+64 a_2 a_{10} \
12 & a_6 a_7+9 a_5 a_8+25 a_4 a_9+49 a_3 a_{10} \
13 & 4 a_6 a_8+16 a_5 a_9+36 a_4 a_{10} \
14 & a_7 a_8+9 a_6 a_9+25 a_5 a_{10} \
15 & 4 a_7 a_9+16 a_6 a_{10} \
16 & a_8 a_9+9 a_7 a_{10} \
17 & 4 a_8 a_{10} \
18 & a_9 a_{10}
end{array}
right)$$
$endgroup$
This is not a proof.
Let $H=frac 1x$ and consider the function
$$f=frac{sum _{i=1}^n i, a_i, x^i}{1+sum _{i=1}^n a_i, x^i}$$ Compute the derivative to get
$$left(1+sum _{i=1}^n a_i, x^i right)^2, f'=left(sum _{i=1}^n i^2 a_i x^{i-1}right) left(1+sum _{i=1}^n a_i
x^iright)-left(sum _{i=1}^n i a_i x^{i-1}right)left( sum _{i=1}^n i a_i
x^iright)$$ The rhs is then a polynomial of degree $2(n-1)$ that is to say
$$text{rhs}=sum_{i=0}^{2(n-1)} b_i,x^i$$ in which the coefficients are all positive since all $a_i$'s are non negative. For example, using $n=10$, we should get
$$left(
begin{array}{cc}
i & b_i \
0 & a_1 \
1 & 4 a_2 \
2 & a_1 a_2+9 a_3 \
3 & 4 a_1 a_3+16 a_4 \
4 & a_2 a_3+9 a_1 a_4+25 a_5 \
5 & 4 a_2 a_4+16 a_1 a_5+36 a_6 \
6 & a_3 a_4+9 a_2 a_5+25 a_1 a_6+49 a_7 \
7 & 4 a_3 a_5+16 a_2 a_6+36 a_1 a_7+64 a_8 \
8 & a_4 a_5+9 a_3 a_6+25 a_2 a_7+49 a_1 a_8+81 a_9 \
9 & 4 a_4 a_6+16 a_3 a_7+36 a_2 a_8+64 a_1 a_9+100 a_{10} \
10 & a_5 a_6+9 a_4 a_7+25 a_3 a_8+49 a_2 a_9+81 a_1 a_{10} \
11 & 4 a_5 a_7+16 a_4 a_8+36 a_3 a_9+64 a_2 a_{10} \
12 & a_6 a_7+9 a_5 a_8+25 a_4 a_9+49 a_3 a_{10} \
13 & 4 a_6 a_8+16 a_5 a_9+36 a_4 a_{10} \
14 & a_7 a_8+9 a_6 a_9+25 a_5 a_{10} \
15 & 4 a_7 a_9+16 a_6 a_{10} \
16 & a_8 a_9+9 a_7 a_{10} \
17 & 4 a_8 a_{10} \
18 & a_9 a_{10}
end{array}
right)$$
answered Jan 22 at 13:00
Claude LeiboviciClaude Leibovici
124k1158135
124k1158135
$begingroup$
Thanks a lot - but what is then the interpretation in regard tothe question of whether we caan know if thederivativeis positive?
$endgroup$
– user37217
Jan 26 at 8:06
$begingroup$
@user37217. You have sums of only positive terms.
$endgroup$
– Claude Leibovici
Jan 26 at 8:43
$begingroup$
Thanks a lot - so this is indeed a proof? - nice!!!
$endgroup$
– user37217
Jan 26 at 13:35
add a comment |
$begingroup$
Thanks a lot - but what is then the interpretation in regard tothe question of whether we caan know if thederivativeis positive?
$endgroup$
– user37217
Jan 26 at 8:06
$begingroup$
@user37217. You have sums of only positive terms.
$endgroup$
– Claude Leibovici
Jan 26 at 8:43
$begingroup$
Thanks a lot - so this is indeed a proof? - nice!!!
$endgroup$
– user37217
Jan 26 at 13:35
$begingroup$
Thanks a lot - but what is then the interpretation in regard tothe question of whether we caan know if thederivativeis positive?
$endgroup$
– user37217
Jan 26 at 8:06
$begingroup$
Thanks a lot - but what is then the interpretation in regard tothe question of whether we caan know if thederivativeis positive?
$endgroup$
– user37217
Jan 26 at 8:06
$begingroup$
@user37217. You have sums of only positive terms.
$endgroup$
– Claude Leibovici
Jan 26 at 8:43
$begingroup$
@user37217. You have sums of only positive terms.
$endgroup$
– Claude Leibovici
Jan 26 at 8:43
$begingroup$
Thanks a lot - so this is indeed a proof? - nice!!!
$endgroup$
– user37217
Jan 26 at 13:35
$begingroup$
Thanks a lot - so this is indeed a proof? - nice!!!
$endgroup$
– user37217
Jan 26 at 13:35
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%2f3072992%2fdifferential-of-iterative-function%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