# Discrete Math

Having probably made my last databases-exam, I started a new course, Discrete Math A.

The last time I studied math was more than 9 years ago, and I found myself puzzling why

(2n+1)^{2 } was not (4n^{2 } + 1).

After 15 minutes of panic, I recalled my second grade math-classes:

(2n+1)^{2 }= 4n^{2} + 4n + 1

because

(2n+1)^{2}

=(2n+1) * (2n+1)

= 2n * 2n, 2n * 1, 1 * 2n, 1*1

= 4n^{2} + 2n + 2n + 1

= 4n^{2} + 4n + 1

pfeeuw.