jika x1 dan x2 akar akar persamaan kuadrat x2-4x+1=0 maka 1/x1+1/x1=

x^2 - 4x + 1 = 0
rumus det

a = 1, b = -4, c = 1
[tex] \frac{-b + \sqrt{ b^{2} - 4ac} }{2a} [/tex]
[tex] \frac{4 + \sqrt{ (-4)^{2} - 4} }{2} [/tex]
[tex] \frac{4 + \sqrt{ 16 - 4} }{2} [/tex]
[tex]\frac{4 + \sqrt{ 12} }{2}[/tex]
[tex]\frac{4 +2 \sqrt{ 3} }{2}= 2 + \sqrt{3} [/tex]

x1 = 2 + √3

[tex] \frac{1}{ x_{1} } + \frac{1}{ x_{1} } = \frac{1}{ 2 + \sqrt{3} } + \frac{1}{ 2 + \sqrt{3} }[/tex]
[tex]\frac{2}{ 2 + \sqrt{3} } = \frac{2}{ 2 + \sqrt{3} }. \frac{2 - \sqrt{3} }{ 2 - \sqrt{3} }=\frac{4 - 2 \sqrt{3} }{ 4 -3 }[/tex]
[tex]4 - 2 \sqrt{3} [/tex]