====== 감마함수 (Gamma Function) ====== ===== 정의 ===== $$ \Gamma (a) = \int_{0}^{\infty} x^{a-1} e^{-x} dx, \ a > 0 $$ set title "Gamma Function" set size 1 set xrange [-4:4] set yrange [-4:4] set zeroaxis plot gamma(x) title "x" ===== 특징 ===== - $$ \Gamma (a) = (a-1) \Gamma (a-1) $$ - $a$가 [[정수]]이면, $\Gamma (a) = (a-1)!$ - $$ \Gamma(1) = 1 $$ - $$ \Gamma (1/2) = \sqrt{\pi} $$ - $$ \int_{0}^{\infty} x^{a-1} e^{-x/b} dx = \Gamma (a) \cdot b^{a} $$ ---- * [[감마함수표]] * [[불완전 감마함수]] * [[정칙 감마함수]] * [[베타함수]] * [[함수]]