Z-axis: always pointing out from the paper (blue in \langle{r, g, b}\rangle)
Standard Equation of a Sphere (surface only): a sphere centered at (a, b, c) with radius r is (x-a)^2 + (y-b)^2 + (z-c)^2 = r^2

unit vector: vector with magnitude 1

i = \langle{1, 0, 0}\rangle

j = \langle{0, 1, 0}\rangle

k = \langle{0, 0, 1}\rangle

\langle{a, b, c}\rangle = a \overrightarrow{i} + b \overrightarrow{j} + c \overrightarrow{k}

normalize vector: divide by its magnitude

vector in component form: \langle{x, y, z}\rangle
express using standard unit vector: i, j, k, 0