hello, i just wish to check that i have done the following correctly:(adsbygoogle = window.adsbygoogle || []).push({});

1. Evaluate [tex] \int d\overarrow{r} [/tex] (r is a vector, and its a closed integral) around the circle C represented by [tex]x^2 + y^2 = a^2[/tex]

what i did here was switch to polars and called [tex]d\overarrow{r}[/tex] ->[tex]rd\theta[/tex] then i noted that r=a and integrated from 0 to 2pi to get the answer as 2pi * a.

and

2. If [tex]\overarrow{f} = x\hat{x} + y\hat{y} + z\hat{z}[/tex]

evaluate [tex]\int \overarrow{f} \cdot d\overarrow{r} [/tex] from (0,0,0) to (1,1,1) along

a) a straight line connecting these points

b) a path from (0,0,0) to (1,0,0) to (1,1,0) to (1,1,1)

for both of these i ended up getting 3/2

for a i just replaced y and z by x and dy and dz by dx and integrated 3x dx...

and for b i got 3/2 by adding up three integrals so i think this should be correct? thanks

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Check integral answers

**Physics Forums | Science Articles, Homework Help, Discussion**