UV আকারের (Integration by parts)

  x3exdx=f(x)+c \int x^{3} e^{x} dx = f{\left ( x \right )} + c হয় তবে f(x)=? 

xneaxdx \int \mathrm{x}^{\mathrm{n}} \mathrm{e}^{\mathrm{ax}} \mathrm{dx}

=eax[xnanxxn1a2+n(n1)xn2a3n(n1)(n2)xn3a4+..]+cx3exdx=ex[x33x2+6x6]+c \begin{array}{l} =\mathrm{e}^{\mathrm{ax}}\left[\frac{\mathrm{x}^{\mathrm{n}}}{\mathrm{a}}-\frac{\mathrm{nx} \mathrm{x}^{n-1}}{\mathrm{a}^{2}}+\frac{\mathrm{n}(\mathrm{n}-1) \mathrm{x}^{\mathrm{n}-2}}{\mathrm{a}^{3}}-\frac{\mathrm{n}(\mathrm{n}-1)(\mathrm{n}-2) \mathrm{x}^{n-3}}{\mathrm{a}^{4}}+. .\right]+c \\ \therefore \int \mathrm{x}^{3} \mathrm{e}^{\mathrm{x}} \mathrm{dx}=\mathrm{e}^{\mathrm{x}}\left[\mathrm{x}^{3}-3 \mathrm{x}^{2}+6 \mathrm{x}-6\right]+c \end{array}

UV আকারের (Integration by parts) টপিকের ওপরে পরীক্ষা দাও