Book:Ephraim J. Borowski/Dictionary of Mathematics/Errata

Sum of Squares of Sine and Cosine

 * cosine

Equilateral Polygon is Equiangular

 * equiangular

Sum of Infinite Geometric Sequence

 * geometric series

Lucas Numbers

 * Lucas numbers

Mersenne Primes

 * Mersenne numbers or Mersenne primes

Octal

 * octal

Pentagonal Number

 * pentagonal number