grandes-ecoles 2015 QII.B.3

grandes-ecoles · France · centrale-maths2__mp Reduction Formulae Derive a Reduction/Recurrence Formula via Integration by Parts
For $( x , y )$ in $\left( \mathbb { R } ^ { + * } \right) ^ { 2 }$, we define $\beta ( x , y ) = \int _ { 0 } ^ { 1 } t ^ { x - 1 } ( 1 - t ) ^ { y - 1 } \mathrm {~d} t$.
Let $x > 0$ and $y > 0$. Establish that $\beta ( x + 1 , y ) = \frac { x } { x + y } \beta ( x , y )$.
For $( x , y )$ in $\left( \mathbb { R } ^ { + * } \right) ^ { 2 }$, we define $\beta ( x , y ) = \int _ { 0 } ^ { 1 } t ^ { x - 1 } ( 1 - t ) ^ { y - 1 } \mathrm {~d} t$.

Let $x > 0$ and $y > 0$. Establish that $\beta ( x + 1 , y ) = \frac { x } { x + y } \beta ( x , y )$.