Given a pixd index $(i,j),$ find the corresponding point $x$ on the imago plane. Note that pixel intex $(1,j)$ refers to the eenter of pixcl $(i,j),$ with pixel $(0,0)$ lecing the bottom left pixel and $(W-1,H-1)$ heing the top right pixel. Note that $p$ is at the corner of the image? not the center of the lower left pixel.

Find the endpoint and $($normalizal$)$ direction of the ray that should loc esst through pixd $(i,j).$