Question

Дано квадратное уравнение x2−14,2x−1,4=0, укажи сумму и произведение корней.
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Answer 1

Ответ: 4 и -45,01

Объяснение:

$x^{2} -14,2x-1,4=0\D=b^{2} -4ac = 14,2^{2} -4*1*1,4=196.04\x_{1} =frac{-b+sqrt{D} }{2a} =frac{4+sqrt{196,04}}{2} =frac{4+2sqrt{49.01}}{2} =frac{2*(2+sqrt{49.01}}{2} =2+sqrt{49.01} \x_{2} =frac{-b-sqrt{D} }{2a} =frac{4-sqrt{196,04}}{2} =frac{4-2sqrt{49.01}}{2} =frac{2*(2-sqrt{49.01}}{2} =2-sqrt{49.01} \x_{1} +x_{2} = 2+sqrt{49.01} +2-sqrt{49.01} =4\x_{1} *x_{2} =(2+sqrt{49.01})*(2-sqrt{49.01}) = 2^{2} -(sqrt{49.01}) ^{2} =4-49.01=-45.01$