Dokažite da jednadžba
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ima realne korijene
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i
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za bilo koje realne koeficijente
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,
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i
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te da su
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i
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korijeni jednadžbe
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.
%V0
Dokažite da jednadžba $x^{2} - (a + c)x + ac - b^{2} = 0$ ima realne korijene $x_{1}$ i $x_{2}$ za bilo koje realne koeficijente $a$, $b$ i $c$ te da su $a$ i $c$ korijeni jednadžbe $(y - x_{1})(y - x_{2}) + b^{2} = 0$.