\hspace{-16}$ Given $\int\frac{1}{(1+\sqrt{x})^{2010}}dx=2.\left\{\frac{1}{\alpha.(1+\ \sqrt{x})^{\alpha}}-\frac{1}{\beta.(1+\sqrt{x})^{\beta}}\right\}+C$\\\\\\ Now Calculating Value of $\int\frac{1}{(1+\sqrt{x})^{2010}}dx$\\\\\\ Put $(1+\sqrt{x})=t\Leftrightarrow \frac{1}{2.\sqrt{x}}dx=dt\Leftrightarrow dx=2\sqrt{x}dt=2.(t-1)dt$\\\\\\ $=\int\frac{2.(t-1)}{t^{2010}}dt=2.\left\{\int\frac{1}{t^{2009}}dt-\int\frac{1}{t^{2010}}dt\right\}$\\\\\\ $=2.\left\{-\frac{1}{2008}.\frac{1}{t^{2008}}+\frac{1}{2009}.\frac{1}{t^{2009}}\right\}+C$\\\\\\ $=2.\left\{-\frac{1}{2008}.\frac{1}{(1+\sqrt{x})^{2008}}+\frac{1}{2009}.\frac{1}{(1+\sqrt{x})^{2009}}\right\}+C$\\\\\\ So Here We get\\\\\\ $\int\frac{1}{(1+\sqrt{x})^{2010}}dx=2.\left\{\frac{1}{2009}.\frac{1}{(1+\sqrt{x})^{2009}}-\frac{1}{2008}.\frac{1}{(1+\sqrt{x})^{2008}}\right\}+C$\\\\\\ So From Here We Get $\boxed{\boxed{\mathbf{\alpha =2009}}}$ and $\boxed{\boxed{\mathbf{\beta =2008}}}$
∫dx/(1+√x)^2010= 2[1/alpha(1+√x)^alpha - 1/beta(1+√x)^beta] +c
where alpha, beta >0
A)|alpha-beta|=1
B)(beta+2)(alpha+1)=20102
C) beta and alpha are in A.P.
D)alpha+1=beta+2=2010
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5 Answers
man111 singh
·2011-10-20 11:15:57
Shubhodip
·2011-10-20 11:31:54
any of option C and D implies the rest..
and you r going to get a q where all options are correct :D
actually its easy..but i got scared in the exam
edit: LOL at the reply below....
man111 singh
·2011-10-20 11:37:15
Yes You are saying Right Shubhodip.
again Thanks. for nice explanation.