# calc

posted by .

is the integral of 2x/(x^3-x)
=-1/2ln(x+1)+1/2ln(x-1)

I got this by doing this:
(\=integral sign)
2\1/(x^2-1)
2\1/(x+1)(x-1)
=A/(x+1)+B/(x-1)
=Ax-A+Bx+B=1
Ax+Bx=0
B-A=1
B=1+A
(1+A)x+Ax=0
x+Ax+Ax=0
1+AB=0
2A=-1
A=-1/2
B+1/2=1, B=1/2
etc.

• calc -

I differ by a factor of 2

2[ A/(x+1) +B/(x-1) ]
A = -1/2, B = +1/2
so
2 int [ -.5 dx/(x+1) + .5 dx /(x-1) ]

1 int [ dx/(x+1) + dx/(x-1) ]

ln (x+1) + ln (x-1)
which is
ln[ (x+1)/(x-1) ]

• calc -

-(1/2)/(x+1) +(1/2)/(x-1)
= [-(1/2)(x-1) + (1/2)(x+1)]/(x^2 -1)
= 1/(x^2-1)
Your riginal integrand is equal to 2/(x^2-1), so your answer seems to be off by a factor of 2.

• calc -

Sorry
ln (x+1)(x-1)
which is
ln(x^2-1)

• calc -

Which I should have seen in the first place.

• calc -

took ya long enuff

• calc -

Yeah, but I am really old :)

## Similar Questions

1. ### Math

Find the integrals. (show steps) (integral sign) xe^(4x^2) I think this how is how its done: (integral sign) xe^(4x^2) it's a u du problem let u=4x^2 so, du=8x dx now you have an x already so all u need is 8 inside and and 1/8 outside …
2. ### calc asap!

can you help me get started on this integral by parts?
3. ### calc

is the integral of xln(x)dx= x^2/4(4ln(x)-4-2ln(x)+3)+C?
4. ### calc

find integral using table of integrals ) integral sin^4xdx this the formula i used integral sin^n xdx =-1/n sin^n-1xcosx +n-1/n integral sin^n-2 using the formula this is what i got: integral sin^4xdx=-1/4sin^3xcosx+3/4 integral sin^2xdx= …
5. ### Calculus

Evaluate the indefinite integral integral sec(t/2) dt= a)ln |sec t +tan t| +C b)ln |sec (t/2) +tan (t/2)| +C c)2tan^2 (t/2)+C d)2ln cos(t/2) +C e)2ln |sec (t/2)+tan (t/2)| +C
6. ### Calculus

Evaluate (integral) cot 2x dx. A. 1/2Ln sin 2x+C B. 1/2Ln cos 2x+C C. 1/2Ln sec 2x+C D. 1/2LN csc 2x+C
7. ### Calculus

I know how to do this problem, but I'm stuck at the arc length differential. Set up an integral for the arc length of the curve. (Do not evaluate the integral) x=y^2ln(y), 1<y<2 dx/dy = 2yln(y) + y ds= sqrt (1 + (2yln(y)+y)^2 …
8. ### Calculus (urgent help)

consider the function f that is continuous on the interval [-5,5] and for which the definite integral 0(bottom of integral sign) to 5(top of integral sign) of f(x)dx=4. Use the properties of the definite integral to evaluate each integral: …
9. ### calculus

consider the function f that is continuous on the interval [-5,5] and for which the definite integral 0(bottom of integral sign) to 5(top of integral sign) of f(x)dx=4. Use the properties of the definite integral to evaluate each integral: …
10. ### calculus (please with steps and explanations)

consider the function f that is continuous on the interval [-5,5] and for which the definite integral 0(bottom of integral sign) to 5(top of integral sign) of f(x)dx=4. Use the properties of the definite integral to evaluate each integral: …

More Similar Questions