418 Glossary
Q the field of rational numbers
R the field of real numbers
C the field of complex numbers
Heron’s Formula The area of a triangle with sides Q, b, c and semi-
perimeter s = f (o + b + c) is J s(s - u)(s - b)(s - c).
Intermediate Value Theorem Let f be a continuous, real-valued func-
tion (in particular, a polynomial) defined on a closed interval [a, b].
Then f assumes on [a, b] every value between f(u) and f(b). If f(u)
and f(b) have opposite signs, then f has a zero in [a, b].