নির্দিষ্ট যোগজ

  23dx(x1)x22x \int_{2}^{3} \frac{dx}{\left ( x - 1 \right ) \sqrt{x^{2} - 2 x}} এর মান__     

SU

23dx(x1)x22x \int_{2}^{3} \frac{\mathrm{dx}}{(\mathrm{x}-1) \sqrt{\mathrm{x}^{2}-2 \mathrm{x}}} \quad । Let, x22x=z22zdz=(2x2)dxzdz=(x1)dx \mathrm{x}^{2}-2 \mathrm{x}=\mathrm{z}^{2} \therefore 2 \mathrm{zdz}=(2 \mathrm{x}-2) \mathrm{dx} \therefore \mathrm{zdz}=(\mathrm{x}-1) \mathrm{dx}

=23(x1)(x22x+1)x22x=23zdz(z2+1)z2=23dzz2+1=[11tan1z]23=[tan1x22x]23=tan13tan10=tan1tanπ3=π3 \begin{array}{l} =\int_{2}^{3} \frac{(x-1)}{\left(x^{2}-2 x+1\right) \sqrt{x^{2}-2 x}}=\int_{2}^{3} \frac{z d z}{\left(z^{2}+1\right) \sqrt{z^{2}}}=\int_{2}^{3} \frac{d z}{z^{2}+1}=\left[\frac{1}{1} \tan ^{-1} z\right]_{2}^{3}=\left[\tan ^{-1} \sqrt{x^{2}-2 x}\right]_{2}^{3} \\ =\tan ^{-1} \sqrt{3}-\tan ^{-1} 0=\tan ^{-1} \tan \frac{\pi}{3}=\frac{\pi}{3} \end{array}

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