What is the Line Integral of a Semicircle with a 45 Degree Angle?

[mefisto666]

so I have a semi circle that goes from

$$\frac{5\pi}{4} to \frac{\pi}{4}$$

so the angle between the x-axis the radius of the circle is 45 degrees.

I have, letting the radius = a)

$$\frac{1}{a} \int \.dl$$

this is going to have an x and y component, I know the x component is 2a in the direction of x, but what about the y component?

 

[LumenPlacidum]

What function are you integrating over that semi-circle?