integration by parts - WHAT AM I DOING WRONGWatch

#1
okay yeah so there is this question it is all "integrate x5ln3x" so i'm like okay i shall integrate this by parts and go

u=ln3x
du/dx= 1/3x

dv/dx=x5
v=x6/6

SO THEN i do

1/6x6ln3x - (the integral of) (1/6x6*1/3x=1/18x5)

= 1/6x6ln3x - 1/108x6 + k

1/36x6(6ln3x-1)+k

so wherrrre am i going wrong? i know i'm probably making a stupid mistake somewhere, but i cant figure it out . i've made a similar mistake on similar questions too
0
9 years ago
#2
The derivative of ln(3x) is just 1/x. Because ln(3x) = ln 3 + ln x, with ln 3 being a constant.
9 years ago
#3
By the chain rule, <-- that's your problem
#4
omfg yeah
0
9 years ago
#5
(Original post by kimoso)
omfg yeah
Lol at this Stick to languages kimoso, anyway how are you doing with your exams? Had the Dutch yet?
0
#6
(Original post by win2kpro)
Lol at this Stick to languages kimoso, anyway how are you doing with your exams? Had the Dutch yet?
nope, that is my last exam! what about you?
0
9 years ago
#7
(Original post by kimoso)
nope, that is my last exam! what about you?
Ooh long wait

Dutch was my first exam! It went very well, im very happy about it

Lets just hope im as happy with the results

0
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