6 + 4√2 = (2 + √2)² => √(6+4√2) = 2+1·√2 => √(6+4√2) ∈ {a+b√2 / a,b∈Z} , unde a = 2 si b = 1
Poti folosi formulele acestea :
[tex] \sqrt{a + \sqrt{b} } = \sqrt{ \frac{a+ \sqrt{a^{2}-b} }{2} } + \sqrt{ \frac{a- \sqrt{a^{2}-b} }{2} } [/tex]
[tex] \sqrt{a -\sqrt{b} } = \sqrt{ \frac{a+ \sqrt{a^{2}-b} }{2} } -\sqrt{ \frac{a- \sqrt{a^{2}-b} }{2} } [/tex]
