int[p(1+p)^(1/2)]
try \(u=1+p\)
\[\int\limits p(1+p)^{1/2} dp\]
u=1+p . du/dp = 1
i'm suppose to use integration by parts but I 'm getting a funny answer
parts? why not \[\int p(\sqrt{1+p})dp\] \[u=1+p, du=dp , p=u-1\] \[\int (u-1)\sqrt{u}du\] \[\int (u^{\frac{3}{2}}-u^{\frac{1}{2}})du\] etc
i know, i want to use integration by parts not substitution
ok so we want \(\int udv = uv-\int vdu\) what do we pick?
not really sure, boss
see i think it will come down to a u - sub using this method as well
we could say \[u=p,dv = \sqrt{1+p}\] and then \[du=dp\] and \[v=\int\sqrt{1+p}dp\]
yep
i guess that will work because \[\int \sqrt{1+p}=2(1+p)^{\frac{3}{2}}\] of i am not mistaken
kk, go on..
so putting it together we get \[uv-\int v du =2p(1+p)^{\frac{3}{2}}-\int 2(1+p)^{\frac{3}{2}}dp\] let me know if i messed up
\[2/3(1+p)^{3/2}\]
yeah right i forget the 3 in the denominator
\[uv-\int v du =\frac{2}{3}p(1+p)^{\frac{3}{2}}-\frac{2}{3}\int (1+p)^{\frac{3}{2}}dp\]should be better
yh
and the last one is ok by power rule, get \[-\frac{3}{2}\int(1+p)^{\frac{3}{2}}dp=-\frac{15}{4}(1+p)^{\frac{5}{2}}\] unless i messed up again
no i messed up again
these \(p\)'s are getting on my nerves. what is wrong with \(x\)?
lol
\[-\frac{2}{3}\int(1+p)^{\frac{3}{2}}dp=-\frac{4}{15}(1+p)^{\frac{5}{2}}\]
there i think that is correct now
yh, prolly
first method is clearly snappier
kk, how do we wrap it up nicely by factorisation ? coz from what we did i got\[2/3[p(1+p)^{3/2}-2/5[(1+p)^{5/2}] +c\]
i will leave that up to you, because i have to bolt
hehe, no p. Thanks you, Master Shifu
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