от ammornil » 15 Окт 2012, 23:08
[tex]A=\left[\frac{2^{\frac{1}{2}}}{(1-x^{2})^{-1}} + \frac{2^{\frac{3}{2}}}{x^{-2}} \right]\hspace{2}:\hspace{2}\left(\frac{x^{-2}}{1+x^{-2}} \right)^{-1}=?[/tex]
[tex]A=\left(\frac{\sqrt{2}}{\frac{1}{1-x^{2}}} + \frac{2.\sqrt{2}}{\frac{1}{x^{2}}} \right)\hspace{2}:\hspace{2}\frac{(x^{-2})^{-1}}{(1+x^{-2})^{-1}}=[\sqrt{2}.(1-x^{2}) + 2.\sqrt{2}.x^{2} ]\hspace{2}:\hspace{2}\frac{x^{2}}{(1+\frac{1}{x^{2}})^{-1}}=\\
=(\sqrt{2}-\sqrt{2}.x^{2} + 2.\sqrt{2}.x^{2})\hspace{2}:\hspace{2}\frac{x^{2}}{(\frac{x^{2}+1}{x^{2}})^{-1}}=(\sqrt{2}+\sqrt{2}.x^{2})\hspace{2}:\hspace{2}\frac{x^{2}}{\frac{x^{2}}{x^{2}+1}}= \\
=[\sqrt{2}(1+x^{2})]\hspace{2}:\hspace{2}\frac{\cancel{x^{2}}.(x^{2}+1)}{\cancel{x^{2}}}=\sqrt{2}.\cancel{(1+x^{2})}\hspace{2}.\hspace{2}\frac{1}{\cancel{(x^{2}+1)}}=\sqrt{2}[/tex]
[tex]\color{lightseagreen}\text{''Който никога не е правил грешка, никога не е опитвал нещо ново.''} \\
\hspace{21em}\text{(Алберт Айнщайн)}[/tex]