Evaluate the integral

CatchThis2

Junior Member
Joined
Feb 6, 2010
Messages
96
(1/x+2/sqrtx)dx

These are the values I used:

U=1/x
DU=lnx
dv=x^-1/2
v=2x^-1/2

Not sure if this is right or not or how to finish off the problem
 
CatchThis2 said:
(1/x+2/sqrtx)dx

These are the values I used:

U=1/x
DU=lnx
dv=x^-1/2
v=2x^-1/2

Not sure if this is right or not or how to finish off the problem

Does your problem look like:

(1x+2x)dx\displaystyle \int \left (\frac{1}{x} + \frac{2}{\sqrt{x}} \right ) dx

If yes then - that reduces to:

=1xdx+2xdx\displaystyle = \int \frac{1}{x} dx + \int \frac{2}{\sqrt{x}} dx

Those are elementary antiderivatives now....
 
Proceed by finding the antiderivatives.

Does it help to see the integrands written exponentially versus rationally/radically?

=x1 dx  +  2x1/2 dx\displaystyle = \int x^{-1} \ dx \;+\; \int 2x^{-1/2} \ dx
 
CatchThis2 said:
Yes, how do I solve from here? Do I uses U substitution?... No - not for most direct approach

Use

for n <> -1

xndx=xn+1n+1+C\displaystyle \int x^n dx = \frac{x^{n+1}}{n+1} + C

for n = -1 you would have a standard anti-derivative.
 
x1dx\displaystyle \int x^{-1} dx

Yes it reduces to what you have which I did. How do you proceed from there?

Hey, pal, if you have no clue on what to do next, then you are wasting yours and this\displaystyle Hey, \ pal, \ if \ you \ have \ no \ clue \ on \ what \ to \ do \ next, \ then \ you \ are \ wasting \ your's \ and \ this

boards time. Do youself and us a favor, and go away.\displaystyle board's \ time. \ Do \ youself \ and \ us \ a \ favor, \ and \ go \ away.
 
Top