Originally Posted by

**BlackadderVII** I can't seem to get a ''nice'' solution to this question, the answer should be a simple fraction not what i get.

The question is 'calculate the line integral of the vector field

v(x,y,z)=((x-1)(z-3),xyz,x+z) along the straight line from (1,1,1) to (1,3,9)

I started by parameterising the line:

d(t)=(1,1,1)+t(0,2,8)

d(t)=(1,1+2t,1+8t)

d'(t)=(0,2,8)

thus v(d(t))=(0,(1+2t)(1+8t),(2+8t)

then i go to work out the integral between 0 and 1 of

<(v(d(t)),d'(t)> dt

and it comes out crap.

Any help would be good, pointing our error or next step

thanks