# Line integral question

1. Apr 1, 2006

### denian

is the first stepc orrect?
TQ.

Last edited by a moderator: May 2, 2017
2. Apr 1, 2006

### eok20

yep, everything looks good.

3. Apr 1, 2006

### Galileo

Yes, that's correct.

But (I guess) you've used a trig identity: $z'(t)=2\sin t \cos t=\sin(2t)$ in the last term. This will not make your integral easier. Best leave it as $2\sin t \cos t$.

4. Apr 1, 2006

### denian

thank you very much, eok and galileo!

5. Apr 1, 2006

i get 7/6

6. Apr 1, 2006

### TD

The correct answer is 7/3 but it shouldn't matter whether you use that trig identity or not.

7. Apr 1, 2006

### denian

tq. i'll try to check back this question later.