Find the magnetic field at the origin

[gkamal]

Yes it is right but just to make sure the B of I3 becomes positive because it's value is negative and it is point in the -x , thus it would be point in the +x with a positive value since 2 negatives cancel right?

btw thank you so much for your help

 

[TSny]

Yes it is right but just to make sure the B of I3 becomes positive because it's value is negative and it is point in the -x , thus it would be point in the +x with a positive value since 2 negatives cancel right?

That's not how I think about it. The field $\vec{B}_3$ produced by $I_3$ is a vector. So, I would not refer to it as being positive or negative. It has a magnitude that is positive. (All vectors have positive magnitude, by definition.) However, when I draw the direction of $\vec{B}_3$ in a sketch using the right hand rule for magnetic fields, I can see that it points to the right. So, the x-component is positive. [Edited]

btw thank you so much for your help

You are welcome. Glad I could be of some help.