# basic line integral question

• Jan 26th 2009, 08:37 AM
mynodelic
basic line integral question
hello, i'm new here and i have a basic question which some of you find silly lol.
i'm studying in thomas calculus section 16.1 :"line integrals"

its a screenshot from the e-book of the example that i didnt understand: (click it)
http://img261.imageshack.us/img261/5...ple1yz9.th.jpg

my question: how did we find those red circled parameters???? if anyone didnt understand my question plz tell me.
• Jan 26th 2009, 08:55 AM
running-gag
Hi

The parametrization of the segment line limited by O(0,0,0) and I(1,1,0) is r(t) = ti + tj, for t between 0 and 1

Take any point M (x,y,z) inside the segment line. OM = r is parallel to OI(1,1,0). This means that exists t such as OM = t OI.
On x axis this gives : x = t
On y axis : y = t
On z axis : z = 0

Therefore M(t,t,0) or OM = ti + tj

I hope my explanation will be of help for you.(Wink)
• Jan 26th 2009, 09:10 AM
mynodelic
can you tell me what happened in C2 plz?