Integration bounds in a continuous charge distribution of a semicircle

[vantz]

Why are the integration bounds from -pi/2 to pi/2 and not 0 to pi?

 

[gneill]

Why are the integration bounds from -pi/2 to pi/2 and not 0 to pi?

Because the angle is with respect to the positive y-axis.

 

[vantz]

what's the proof? I can't understand why this is the case

Thank you

 

[gneill]

what's the proof? I can't understand why this is the case

Thank you

Look at the diagram. Note where the angle θ is. If θ was 2π, where would that put the radius vector?