can someone please help me with double integration
\[\int\limits_{0}^{1 } \int\limits_{5y}^{5} e^(x^2)\] that should be e^(x^2)
Ive tried this several times and keep getting the wrong answer
tell me how you did it please
we need to change the order of integration i hope you understand it
i tried to do it dx dy
but you can solve e^(x^2) dx
yes i got 2xe^(x^2)
it is incorrect..
and then with the limit 10e^10 - 10ye^10y dy
take the derivative of this and see that it is not e^(x^2)
[2xe^(x^2)]' = 2(e^(x^2) + x* (2x) * e^(x^2)) and this is not e^(x^2)
you cant integrate e^(x^2) normally ..
we have to change limits and hope that then we will be able to integrate..
ok so how do we do that?
wait i did a mistake in my sketch
i deleted and drawing again :
|dw:1350765581790:dw|
now if we want to change the order of integration we have to change the limits so if we want dydx we get: \[\int\limits_{0}^{5} \int\limits_{0}^{\frac{ x }{ 5 }} e^{x^2} dydx\]
tell me if you understand how i changed the limits
solving this integral gives \[\int\limits_{0}^{5} \frac{ x }{ 5 } \times e^{x^2} - 0 \times e^{x^2} dx = \int\limits_{0}^{5} \frac{ x }{ 5 } \times e^{x^2} dx\]
now we can do it!! since we may call u = x^2 du = 2xdx so du/2 = xdx \[\int\limits_{0}^{25} \frac{ e^{u} }{ 10 }du\] = (e^25) / 10 - 1/10 = (e^(25) - 1)/10
Let me know when you read this
ok i read it
understand what i did?
kind of
im not really sure how the limits changed i guess i thought i got it but i guess i dont
the first limits was according to dxdy so : |dw:1350766770708:dw|
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