Can someone please help me integrate these problems attached?
Cinnnnn! Where's the attachment lady? c:
sorry lol
can you see it
there is an s \[\int\limits_{-14}^{1}s \left| 4-s^2 \right|\]
Oh oh oh, didn't see that >.< ty
sorry 49 still typo
\[\Large\rm \int\limits\limits_{-14}^1s\left|49-s^2\right|ds\]
correct
Lemme see if this makes sense.... \[\Large\rm \left|49-s^2\right|=\left|(7-s)(7+s)\right|\] \[\Large\rm =\cases{-(7-s)(7+s), &s < -7\\ \rm \quad(7-s)(7+s), &-7 < s < 7}\]Do you understand what I'm doing with the pieces here? Ahhh I can't.... words.... blah
yes you broke it down because it is an absolute value
So we have to rewrite our integral as the sum of two integrals. We need to break up the boundary at -7
ok
would the bounds be -14 to -7 and -7 to 1
Yes those bounds sound correct c:
ok and then we integrate
\[\Large\rm \int\limits\limits_{-14}^{-7}-s(49-s^2)ds+\int\limits_{-7}^1 s(49-s^2)ds\]So I wrote these back as squares because we'll want to apply a substitution. Easier to do so without factoring it. The factoring was just to see where the bad spots were in our absolute.
ok I see question how did you know to split it at -7?
Oh boy.. how to put this into words.. ummm
|dw:1408507574855:dw|If you look at the function y=x,
uhhhm
|dw:1408507610842:dw|And take the absolute value of x, what you're really doing is, applying a negative to the x when x is negative. That's what flips the branch up to being positive on the left side. That's what the absolute function does, it applies a negative if we would be negative, changing it to positive in the end.
So when we have a factor of |7+s|, when we're below -7, the inside is negative, so the absolute function tells us to apply a negative
Bahh this is the worst explanation >.<
lol
Yes I understand that, but in this equation would you just look for where the function became negative and that would be your bound
no it was good
|dw:1408507831863:dw|
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