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QRAwarrior
 2 years ago
Evaluate the definite integral from u = 0 to u = 4 of:
\sqrt{1 + u^2}
dx
As you may have noticed, I have already done Usub.
QRAwarrior
 2 years ago
Evaluate the definite integral from u = 0 to u = 4 of: \sqrt{1 + u^2} dx As you may have noticed, I have already done Usub.

This Question is Closed

Mimi_x3
 2 years ago
Best ResponseYou've already chosen the best response.0Then where do you needhelp with?

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0Where do you people get your bike avatars from?

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0I do not want "Google" as an answer... :O

lgbasallote
 2 years ago
Best ResponseYou've already chosen the best response.0looks trig sub...have you learned that yet?

lgbasallote
 2 years ago
Best ResponseYou've already chosen the best response.0but we really did gust google this! i swear! :(

Mimi_x3
 2 years ago
Best ResponseYou've already chosen the best response.0What's the whole question?

lgbasallote
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1337521244254:dw

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1337521266266:dw

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0Yes I know that trig sub.

lgbasallote
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1337521291094:dw

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0But ultimately, you have to put a 4 into a trigonometric function's argument. How will that work?

Mimi_x3
 2 years ago
Best ResponseYou've already chosen the best response.0the problem is subbing in the limits???

LagrangeSon678
 2 years ago
Best ResponseYou've already chosen the best response.1convert the limits when using the trig sub

lgbasallote
 2 years ago
Best ResponseYou've already chosen the best response.0dont forget to change back to x before evaluating

Mimi_x3
 2 years ago
Best ResponseYou've already chosen the best response.0No, you don't need to convert back

lgbasallote
 2 years ago
Best ResponseYou've already chosen the best response.0otherwise you'll have to convert the limits in terms of theta

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0Ok let me see what happens:  tan(θ) = u/1  sec(θ) = \sqrt{1 + u^2} Then, sec^2(θ)dθ = du

lgbasallote
 2 years ago
Best ResponseYou've already chosen the best response.0yep.. \[\int \sec^3 \theta d\theta\]

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0Then what is limits of integration wrt θ?

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0How did you get that?

lgbasallote
 2 years ago
Best ResponseYou've already chosen the best response.0it was sec^3 theta...ohh woops

lgbasallote
 2 years ago
Best ResponseYou've already chosen the best response.0sec^3 theta = (sec^2 theta)sec theta (1+ tan^2 theta) sec theta \[\int \sec \theta + \tan^2 \theta \sec \theta\] lol got me stuck now

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0dw:1337523905957:dw @LagrangeSon678 @shivam_bhalla

experimentX
 2 years ago
Best ResponseYou've already chosen the best response.1evaluate it individually .. \[ \int \sec \theta d\theta = \ln \sec\theta + \tan\theta\]

experimentX
 2 years ago
Best ResponseYou've already chosen the best response.1this is a lot better http://answers.yahoo.com/question/index?qid=20110524035942AAXxTdM

shivam_bhalla
 2 years ago
Best ResponseYou've already chosen the best response.1@QRAwarrior , i just remember this \[\int\limits_{}^{}\sqrt{x^2+a^2} = \frac{x}{2}\sqrt{x^2+a^2}+\frac{a^2}{2}\log{x+\sqrt{x^2+a^2}}+C\]

shivam_bhalla
 2 years ago
Best ResponseYou've already chosen the best response.1You can go ahead and derive this

shivam_bhalla
 2 years ago
Best ResponseYou've already chosen the best response.1I forgot the dx in the question :P

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0Ok, skrew that question and instead would you mind looking at this: You have the curves x = (y7)^2, and x = 4 that enclose a region. You must rotate this region about y = 5. dw:1337525316103:dw I need to use the shell method here, but it looks like as if I will get two cylinders here. Thanks for the help on the opening post question...

experimentX
 2 years ago
Best ResponseYou've already chosen the best response.1I think that's formula for standard integral ... what do we call it ... i have bunch of them in my books ... but they are derived in the same way!!

shivam_bhalla
 2 years ago
Best ResponseYou've already chosen the best response.1slight Correction: \[\int\limits\limits_{}^{}\sqrt{x^2+a^2} \space \space dx = \frac{x}{2}\sqrt{x^2+a^2}+\frac{a^2}{2}\log{x+\sqrt{x^2+a^2}}+C\]

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0@shivam_bhalla look at my recent post above

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0Those are two functions!

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0I just realized! I would have to use the washer.

shivam_bhalla
 2 years ago
Best ResponseYou've already chosen the best response.1@QRAwarrior , I am not so good at this. @TuringTest can surely help you in this :)

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0Alright thanks your help for the above.

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0@TuringTest help please @amistre64 @Hero @asnaseer

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0@FoolForMath would you mind helping me here?

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0Someone is bound to come!

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0@apoorvk help please?

QRAwarrior
 2 years ago
Best ResponseYou've already chosen the best response.0Please look at the most recent question (it is the one with the sketch just above, NOT THE OPENING POST)

experimentX
 2 years ago
Best ResponseYou've already chosen the best response.1http://www.wolframalpha.com/input/?i=x+%3D+%28y7%29^2%2C++x%3D4 \[ \int_{5}^{9}2\pi (y7)(y7)^2 dy\]
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