(Solved): A positively charged disk of radius R and total charge Qdisk lies in the xz plane, centered on ...

A positively charged disk of radius $$R$$ and total charge $$Q_{\text{disk }}$$ lies in the $$xz$$ plane, centered on the $$y$$ axis (see figure below). Also centered on the $$y$$ axis is a charged ring with the same radius as the disk and total charge Qring. The ring is a distance $$d$$ above the disk. Determine the electric field at the point $$P$$ on the $$y$$ axis, where $$P$$ is above the ring a distance $$y$$ from the origin. (Use any variable or symbol stated above along with the following as necessary: $$k$$.) magnitude $$E=\left\{\frac{2k{Q}_{disk}}{R^2}\left[1?\frac{y}{\sqrt{\left(y^2+R^2\right)}}\right]+k{Q}_{\text{ring }}\left[y?\frac{d}{\left((y?d{)}^2+R^2\right)}\right]\right\}x$$ direction