Evaluate the integral using the substitution rule
The integral is $$int_0^4 frac{2t}{sqrt{1+2t}} ,dt$$
I set $u = 1+2t$ and got that $du = 2 dt$, which makes $dt = du/2$. After this, I am confused as to what to do because $2t$ is still in the equation.
(Also, I'm not sure how to format the equation on here so I apologize if there is any confusion)
calculus definite-integrals
add a comment |
The integral is $$int_0^4 frac{2t}{sqrt{1+2t}} ,dt$$
I set $u = 1+2t$ and got that $du = 2 dt$, which makes $dt = du/2$. After this, I am confused as to what to do because $2t$ is still in the equation.
(Also, I'm not sure how to format the equation on here so I apologize if there is any confusion)
calculus definite-integrals
You started correctly, and you are aware of importance to have only $u$ after the substitution. Good! Now replace in your integral $2t$ by $u-1$ and you can continue
– user376343
Nov 27 '18 at 20:05
If $u=2t+1$ then $2t=u-1$ right? Replace it and it's done.
– Ramiro Scorolli
Nov 27 '18 at 20:06
add a comment |
The integral is $$int_0^4 frac{2t}{sqrt{1+2t}} ,dt$$
I set $u = 1+2t$ and got that $du = 2 dt$, which makes $dt = du/2$. After this, I am confused as to what to do because $2t$ is still in the equation.
(Also, I'm not sure how to format the equation on here so I apologize if there is any confusion)
calculus definite-integrals
The integral is $$int_0^4 frac{2t}{sqrt{1+2t}} ,dt$$
I set $u = 1+2t$ and got that $du = 2 dt$, which makes $dt = du/2$. After this, I am confused as to what to do because $2t$ is still in the equation.
(Also, I'm not sure how to format the equation on here so I apologize if there is any confusion)
calculus definite-integrals
calculus definite-integrals
edited Nov 28 '18 at 11:58
N. F. Taussig
43.6k93355
43.6k93355
asked Nov 27 '18 at 19:59
CodeGuy7153
92
92
You started correctly, and you are aware of importance to have only $u$ after the substitution. Good! Now replace in your integral $2t$ by $u-1$ and you can continue
– user376343
Nov 27 '18 at 20:05
If $u=2t+1$ then $2t=u-1$ right? Replace it and it's done.
– Ramiro Scorolli
Nov 27 '18 at 20:06
add a comment |
You started correctly, and you are aware of importance to have only $u$ after the substitution. Good! Now replace in your integral $2t$ by $u-1$ and you can continue
– user376343
Nov 27 '18 at 20:05
If $u=2t+1$ then $2t=u-1$ right? Replace it and it's done.
– Ramiro Scorolli
Nov 27 '18 at 20:06
You started correctly, and you are aware of importance to have only $u$ after the substitution. Good! Now replace in your integral $2t$ by $u-1$ and you can continue
– user376343
Nov 27 '18 at 20:05
You started correctly, and you are aware of importance to have only $u$ after the substitution. Good! Now replace in your integral $2t$ by $u-1$ and you can continue
– user376343
Nov 27 '18 at 20:05
If $u=2t+1$ then $2t=u-1$ right? Replace it and it's done.
– Ramiro Scorolli
Nov 27 '18 at 20:06
If $u=2t+1$ then $2t=u-1$ right? Replace it and it's done.
– Ramiro Scorolli
Nov 27 '18 at 20:06
add a comment |
3 Answers
3
active
oldest
votes
HINT
Note that $2t = u-1$ and you get
$$
int frac{u-1}{sqrt{u}}frac{du}{2}
$$
which cleanly splits into 2 integrals
I can't believe I missed that, thank you!
– CodeGuy7153
Nov 27 '18 at 20:10
add a comment |
Keep going.
Well, students forget that the sub they make can be manipulated. Let $u = 1 + 2t$, so then $2t = u -1.$ Now the integral is
$$ int_1 ^9 frac{u-1}{2sqrt{u}} du $$
which is easy to do once you properly separate the fraction.
add a comment |
An other aproach
$$I=int_0^4frac{1+2t-1}{sqrt{1+2t}}dt=$$
$$int_0^4sqrt{1+2t}dt-int_0^4frac{dt}{sqrt{1+2t}}$$
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%2f3016226%2fevaluate-the-integral-using-the-substitution-rule%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
HINT
Note that $2t = u-1$ and you get
$$
int frac{u-1}{sqrt{u}}frac{du}{2}
$$
which cleanly splits into 2 integrals
I can't believe I missed that, thank you!
– CodeGuy7153
Nov 27 '18 at 20:10
add a comment |
HINT
Note that $2t = u-1$ and you get
$$
int frac{u-1}{sqrt{u}}frac{du}{2}
$$
which cleanly splits into 2 integrals
I can't believe I missed that, thank you!
– CodeGuy7153
Nov 27 '18 at 20:10
add a comment |
HINT
Note that $2t = u-1$ and you get
$$
int frac{u-1}{sqrt{u}}frac{du}{2}
$$
which cleanly splits into 2 integrals
HINT
Note that $2t = u-1$ and you get
$$
int frac{u-1}{sqrt{u}}frac{du}{2}
$$
which cleanly splits into 2 integrals
answered Nov 27 '18 at 20:03
gt6989b
33k22452
33k22452
I can't believe I missed that, thank you!
– CodeGuy7153
Nov 27 '18 at 20:10
add a comment |
I can't believe I missed that, thank you!
– CodeGuy7153
Nov 27 '18 at 20:10
I can't believe I missed that, thank you!
– CodeGuy7153
Nov 27 '18 at 20:10
I can't believe I missed that, thank you!
– CodeGuy7153
Nov 27 '18 at 20:10
add a comment |
Keep going.
Well, students forget that the sub they make can be manipulated. Let $u = 1 + 2t$, so then $2t = u -1.$ Now the integral is
$$ int_1 ^9 frac{u-1}{2sqrt{u}} du $$
which is easy to do once you properly separate the fraction.
add a comment |
Keep going.
Well, students forget that the sub they make can be manipulated. Let $u = 1 + 2t$, so then $2t = u -1.$ Now the integral is
$$ int_1 ^9 frac{u-1}{2sqrt{u}} du $$
which is easy to do once you properly separate the fraction.
add a comment |
Keep going.
Well, students forget that the sub they make can be manipulated. Let $u = 1 + 2t$, so then $2t = u -1.$ Now the integral is
$$ int_1 ^9 frac{u-1}{2sqrt{u}} du $$
which is easy to do once you properly separate the fraction.
Keep going.
Well, students forget that the sub they make can be manipulated. Let $u = 1 + 2t$, so then $2t = u -1.$ Now the integral is
$$ int_1 ^9 frac{u-1}{2sqrt{u}} du $$
which is easy to do once you properly separate the fraction.
answered Nov 27 '18 at 20:04
Sean Roberson
6,40531327
6,40531327
add a comment |
add a comment |
An other aproach
$$I=int_0^4frac{1+2t-1}{sqrt{1+2t}}dt=$$
$$int_0^4sqrt{1+2t}dt-int_0^4frac{dt}{sqrt{1+2t}}$$
add a comment |
An other aproach
$$I=int_0^4frac{1+2t-1}{sqrt{1+2t}}dt=$$
$$int_0^4sqrt{1+2t}dt-int_0^4frac{dt}{sqrt{1+2t}}$$
add a comment |
An other aproach
$$I=int_0^4frac{1+2t-1}{sqrt{1+2t}}dt=$$
$$int_0^4sqrt{1+2t}dt-int_0^4frac{dt}{sqrt{1+2t}}$$
An other aproach
$$I=int_0^4frac{1+2t-1}{sqrt{1+2t}}dt=$$
$$int_0^4sqrt{1+2t}dt-int_0^4frac{dt}{sqrt{1+2t}}$$
answered Nov 27 '18 at 20:09
hamam_Abdallah
38k21634
38k21634
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.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- 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.
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%2f3016226%2fevaluate-the-integral-using-the-substitution-rule%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
You started correctly, and you are aware of importance to have only $u$ after the substitution. Good! Now replace in your integral $2t$ by $u-1$ and you can continue
– user376343
Nov 27 '18 at 20:05
If $u=2t+1$ then $2t=u-1$ right? Replace it and it's done.
– Ramiro Scorolli
Nov 27 '18 at 20:06