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ta123
 3 years ago
Best ResponseYou've already chosen the best response.1hey you know on the other problem you were helping me with lagrange?

ta123
 3 years ago
Best ResponseYou've already chosen the best response.1what did you get for the answer because I got 4 and they counted it wrong

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1are u sure you evaluated correctly

ta123
 3 years ago
Best ResponseYou've already chosen the best response.1oh, made a stupid sign error

ta123
 3 years ago
Best ResponseYou've already chosen the best response.1could you help me with this new problem on the attachment

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1yeah let me look at it

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1okay so this is what you wanna do, set u=x+4, then you have to then rewrite x in terms of u. You can do this simply by saying x=u4

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1dw:1321490017407:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1dw:1321490044699:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1dw:1321490067161:dw

ta123
 3 years ago
Best ResponseYou've already chosen the best response.1do you replug the original function into u after integrating

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1yes after you, integrate, you must replace the orginal function

ta123
 3 years ago
Best ResponseYou've already chosen the best response.1did you get u^2/23x*2U^(1/2) after integrating

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1i led you wrong, my mistake. What you want to do, is let u=sqrt(x+4), now we rewrite x interm of u. To do this simply:dw:1321490856188:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1okay, now you should get:dw:1321490948435:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now let fix up that integral:dw:1321491019469:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1dw:1321491091199:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now recall that u=sqrt(x+4), thus we can divide out the u in the denmominator and the sqrt(x+4) as so:dw:1321491198348:dw The two can be put outside the integral since it is a constant

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now simply we have:dw:1321491263984:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1next you have to integrate that, and then replace the u's. Then evaluate over your limits

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1or, we could simply change the limits interms of u. Which would actaully be much eaier in this case. But i leave that up to you to decide on

ta123
 3 years ago
Best ResponseYou've already chosen the best response.1sqrt(x+4) did both cancel out and when you replace the u on the bottom back to x+4 don't you have to do the same thing to the top?

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1on top we had u^23, cause we replaced the x remeber

ta123
 3 years ago
Best ResponseYou've already chosen the best response.1oh, ok also you forgot to label the endpoints on the integral

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1well,i didnt forget, for me it is simpler to first leave the limits while i do the integration, since they really dont matter untill we get the antiderivative, which we then evlauate over the limits

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1yes i did,1 is the correct answer

ta123
 3 years ago
Best ResponseYou've already chosen the best response.1Thanks could you help me with one more of these problem?

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1did you post it already?

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1yeah, okay lets do this, can we multiply the x into the brackets, then seperate the integral into two spereate integrals:dw:1321500013159:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now lets take out some constants: dw:1321500075388:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now let try this, can we for the first integral, let x^2=u, then du=2xdx, which further means du/2x=dx

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now it should look something like this:dw:1321500219046:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now we see that the x will divide out, and the 1/2 from the du can be taken outside the integral, so now we will get :dw:1321500319063:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now 2*1/2 is simply 1, so we now have:dw:1321500384165:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now we can integrate

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1for the first integral, what i the antiderivative of f'? well its simply f, the orginal function , and the second integral is very simpyle to integrate

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1dw:1321500486597:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1dw:1321500522223:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1but lets replace the u:dw:1321500561883:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1now you can evaluate this over you limits but remeber that you were given certain conditions, namely f(1)=3 and f(0)=1.so we havedw:1321500688385:dw

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1furthermore:dw:1321500784828:dw

ta123
 3 years ago
Best ResponseYou've already chosen the best response.1yes, I was just was reviewing all the work, thanks!

LagrangeSon678
 3 years ago
Best ResponseYou've already chosen the best response.1anytime:)soon you will be an expert on calculus and you will be helping others as well
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