Risolvere la seguente espressione
[math]\sqrt{a^2/5-1+4/(5a^2)}:(\sqrt(a-3+2/a)\sqrt((a^2+a)/(5a+10)))=[/math]
[math]\sqrt{a^2/5-1+4/(5a^2)}:(\sqrt(a-3+2/a)\sqrt((a^2+a)/(5a+10)))=[/math]
[math]=\sqrt{(a^4-5a^2+4)/(5a^2)}:(\sqrt((a^2-3a+2)/a)\sqrt((a(a+1))/(5(a+2))))=[/math]
Essendo
[math]a^4-5a^2+4=(a^2-4)(a^2-1)[/math]
e
[math]a^2-3a+2=(a-2)(a-1)[/math]
si ha
[math]=\sqrt{(a^4-5a^2+4)/(5a^2)}:(\sqrt((a^2-3a+2)/a)\sqrt((a(a+1))/(5(a+2))))=[/math]
[math]=\sqrt{((a^2-4)(a^2-1))/(5a^2)}:(\sqrt(((a-2)(a-1))/a)\sqrt((a(a+1))/(5(a+2))))=[/math]
Semplificando
[math]=\sqrt{((a^2-4)(a^2-1))/(5a^2)}:(\sqrt(((a-2)(a-1)(a+1))/(5(a+2)))=[/math]
[math]=\sqrt{((a-2)(a+2)(a-1)(a+1))/(5a^2)(5(a+2))/((a-2)(a-1)(a+1))}=[/math]
Semplificando ancora si ottiene
[math]=\sqrt{(a+2)^2/(a^2)}=|(a+2)/a|[/math]
.