Предмет: Алгебра, автор: malika15kz

X²-(√2+1)x+√2=0 помогите

Ответы

Автор ответа: XXX96
0
x^2-( sqrt{2}+1)x+ sqrt{2}=0\D=(-( sqrt{2}+1)^2-4*1* sqrt{2}=\=2+2 sqrt{2}+1-4 sqrt{2}=3-2 sqrt{2}\\x_1= frac{ sqrt{2}+1- sqrt{3-2 sqrt{2} }  }{2} = frac{ sqrt{2}+1- sqrt{3- sqrt{8} }  }{2}\\x_2= frac{ sqrt{2}+1+ sqrt{3-2 sqrt{2} }  }{2} = frac{ sqrt{2}+1- sqrt{3- sqrt{8} }  }{2}\\sqrt{3- sqrt{8}}= sqrt{ frac{3+ sqrt{3^2-8} }{2} }- sqrt{ frac{3- sqrt{3^2-8} }{2} }= sqrt{ frac{3+1}{2} }- sqrt{ frac{3-1}{2} }= sqrt{2}-1
x_1= frac{ sqrt{2}+1-( sqrt{2}-1 ) }{2}= frac{ sqrt{2}+1- sqrt{2}+1  }{2}= frac{2}{2}=1\\x_2= frac{ sqrt{2}+1+( sqrt{2}-1 ) }{2}= frac{ sqrt{2}+1+ sqrt{2}-1  }{2}= frac{2 sqrt{2} }{2}= sqrt{2}

Ответ: 1 и √2
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