
Andrea O. answered 04/15/15
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∫(1/(x+1))-(8x)1/3 dx
For this problem you can work with it in parts because you subtracting, you can also do it with addition but not multiplying or dividing
∫(1/(x+1)) dx - ∫(8x)1/3 dx
Lets solve the first part
∫(1/(x+1)) dx
If you don't know the derivative of ln(x) is 1/x so for this problem the anti-derivative is:
ln|x+1| +C1
Now for the second part
- ∫(8x)1/3 dx for this you can leave the negative outside the integral so you don't have to worry about it
so the formula for this is:
∫ axn dx = axn+1 / n +1
So for our problem
a = 8
n = 1/3
n+1= (1/3) + (3/3) = 4/3
The anti-derivative is:
=(8x4/3 ) / (4/3) but here you are dividing by a fraction so you get
=3•8x4/3 / 4
=6x4/3 + C2
Now we can put all the parts together and don't forget to bring back the negative sign
ln|x+1| +C1 - 6x4/3 - C2
now C1 - C2 will just equal another constant so I will just call that C
ln|x+1| - 6x4/3 + C