Question

∫(5x^3 e^4x )dx evaluate in parts

Answer 1

5x^3 = u
e^4x = dv

Answer 2

example

Answer 3

in the picture you have 5x^2 instead of 5x^3 .. so whats the real number?

Answer 4

thats just an example of how it needs to be worked out from a hw problem

Answer 5

the problem is 5x^3

Answer 6

\[∫(5x^3 e^4x )dx \]

Answer 7

isnt it e^(4x) ?

Answer 8

yes srry

Answer 9

\[∫▒(5x^3 e^{4x})x \]

Answer 10

how did you enter it in wolfram

Answer 11

With the correct parenthisis.. "integrate (5x^3* e^(4x) )dx"

Answer 12

how did you get it in parts

Answer 13

my first post

Answer 14

for example how would you evaluate this one

Answer 15

5x^3 = u
e^(4x) = dv

the formula is: \[\int\limits_{}^{}u*dv = u*v - \int\limits_{}^{}v*du\]

Answer 16

\[∫_0^4(4e^5+ 3x)dx ]\] jus[t evaluate

Answer 17

it gives the answer but not the steps

Answer 18

press the Steps button on Wolfram alpha...

Answer 19

right it doesnt show that type it and see

Answer 20

it doesnt let you type integrate for that one and i dont need it in parts just need it to be evaluated

Answer 21

5x^3 = u
e^(4x) = dv
the formula is: ∫u∗dv=u∗v−∫v∗du

du = 15x^2
v = ∫e^(4x) dx= e^(4 x)/4

now you just need to use this formula untill the "u" disappear..

now your u = 15x^2
dv = e^(4 x)/4 dx

derivate the "u" and integrate the "dv" again

du = 30x
v = ∫ e^(4 x)/4 dx = e^(4 x)/16

apply the formula one last time to eliminate the "u"

u = 30x (=) du = 30.

now its just a simple integral

Answer 22

what you mean by evaluating an integral?

Answer 23

one sec... will post an example

Answer 24

but you can only evaluate the integral after solving it.
First you need to solve it by parts as I already exaplained.
when you get the last result 5/128 e^(4 x) (32 x^3-24 x^2+12 x-3)

now you can evaluate it..