- Elementary algebra (Wikipedia)
Elementary algebra, also known as college algebra, encompasses the basic concepts of algebra. It is often contrasted with arithmetic: arithmetic deals with specified numbers, whilst algebra introduces variables (quantities without fixed values).
- Omega2 Cygni (Wikipedia)
Omega2 Cygni, Latinized from ω2 Cygni, is the Bayer designation for a solitary star in the northern constellation of Cygnus. It has an apparent visual magnitude of 5.5, which is faintly visible to the naked eye on a dark night. Based upon an annual parallax shift of 8.17 mas, it is located roughly 399 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.08 due to interstellar dust.