# Badly need help with Line Integrals

• May 11th 2012, 11:17 PM
linalg123
Badly need help with Line Integrals
Calculate the line integral

$\int$c F dr

where c is given by r(t) = < t, t^2, t^3> , 0<= t <= 1
and F(x,y,z) = (sin(y) - y^2sin(x) , xcosy + 2ycosx , 1)

really not sure how to get started on this. any help would be great
• May 13th 2012, 09:58 PM
linalg123
Re: Badly need help with Line Integrals
anyone?
• May 14th 2012, 07:02 AM
HallsofIvy
Re: Badly need help with Line Integrals
It's really just straightforward calculation. r(t) = < t, t^2, t^3> so dr= <1, 2t, 3t^2> dt.

F(x,y,z) = <sin(y) - y^2sin(x) , xcosy + 2ycosx , 1> so F dr= (sin(y)- y^2sin(x))+ 2t(xcos(y)- 2ycos(x))+ 3t^2)dt

Now replace x and y in that by t and t^2, respectively. Then integrate from t= 0 to t= 1.