Definite Integral

An Integral

$$\int_a^b f(x)\,dx$$

with upper and lower limits. The first Fundamental Theorem of Calculus allows definite integrals to be computed in terms of Indefinite Integrals, since if $F$ is the Indefinite Integral for $f(x)$, then

$$\int_a^b f(x)\,dx = F(b)-F(a).$$

See also Calculus, Fundamental Theorems of Calculus, Indefinite Integral, Integral