[tex]<=>\sqrt{3+2\sqrt{2}}^n+\frac{1}{\sqrt{3+2\sqrt{2}}^n}=6<=>(\sqrt{3+2\sqrt{2}}^n)^2-6\sqrt{3+2\sqrt{2}}^n+1=0<=>\sqrt{3+2\sqrt{2}}^n=3\pm 2\sqrt{2}<=>n=2,-2[/tex]
vì n nguyên dương nên chỉ nhận n=2
[tex]<=>\sqrt{3+2\sqrt{2}}^n+\frac{1}{\sqrt{3+2\sqrt{2}}^n}=6<=>(\sqrt{3+2\sqrt{2}}^n)^2-6\sqrt{3+2\sqrt{2}}^n+1=0<=>\sqrt{3+2\sqrt{2}}^n=\sqrt{3\pm 2\sqrt{2}}<=>n=1,-1[/tex]
vì n nguyên dương nên chỉ nhận n=1
[tex]<=>\sqrt{3+2\sqrt{2}}^n+\frac{1}{\sqrt{3+2\sqrt{2}}^n}=6<=>(\sqrt{3+2\sqrt{2}}^n)^2-6\sqrt{3+2\sqrt{2}}^n+1=0<=>\sqrt{3+2\sqrt{2}}^n=3\pm 2\sqrt{2}<=>n=2,-2[/tex]
vì n nguyên dương nên chỉ nhận n=2