what is the integral of ((1+sqrt.x)^1/3)/(sqrt.x)
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http://www.wolframalpha.com/input/?i=ntegral+of+%28%281%2Bsqrt%28x%29%5E1%2F3%29%2F%28sqrt%28x%29
I got 2/3*(1+sqrt.x)^3/2
click on show steps
that not the right problem
no i think not. if you want to cheat you have to be careful
i dont want to cheat, i worked it out and got 2/3*(1+sqrt.x)^3/2
rather simple u-sub yes? \[\int\frac{\sqrt[3]{1+\sqrt{x}}}{\sqrt{x}}dx\]
right
u=1+sqrt.x
put \[u=1+\sqrt{x}\] \[du=\frac{1}{2\sqrt{x}}\] get \[\frac{1}{2}\int\sqrt[3]{u}du\]
get \[\frac{1}{2}\times \frac{3}{4}u^{\frac{4}{3}}\] \[=\frac{3}{8}\sqrt[3]{(1+\sqrt{x}})^4\]
oh no mistake!!
sorry the constant out front should be 2, not 1/2
\[du=\frac{1}{2\sqrt{x}}dx\] \[2du=\frac{dx}{\sqrt{x}}\]
so instead of \[\frac{3}{8}\] it should be \[\frac{3}{2}\] out front. my mistake
oh its raised to 4/3
dont tell me the answer yet
ok i let you finish it
i got it it is :
close but you are off by a constant.
+ C
should be \[\frac{3}{2}\] not \[\frac{3}{4}\]
no i meant the constant out front. because when you do the u-sub you do not get \[du=\frac{1}{\sqrt{x}}dx\] you get \[du=\frac{1}{2\sqrt{x}}dx\]
so you get \[2du=\frac{1}{\sqrt{x}}dx\] pull the 2 out front
that is why it should be \[\frac{3}{2}\] not \[\frac{3}{4}\]
but i took the derivative of the answer i got and it gave the integral
no. the derivative of \[\sqrt{x}=\frac{1}{2\sqrt{x}}\]
so you will be off by a factor of 2
\[\frac{d}{dx}\frac{3}{4}(1+\sqrt{x})^{\frac{4}{3}}\] \[=\frac{4}{3}\times \frac{3}{4}(1+\sqrt{x})^{\frac{1}{3}}\times \frac{1}{2\sqrt{3}}\]
so with out the extra two out front you have the wrong answer. but easy to fix, just multiply by 2
can you cheack my work
i am there
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