Question

Dadas as funções abaixo, ache as raízes de cada função.

a) Y=x²+5

b) Y=-x²+49

c) Y=x²-9x+14

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Answer 1

Resposta:

Explicação passo-a-passo:

$a)x^2+5=0\\x^=-5\\x=^+_-\sqrt{-5}\\x=^+_-\sqrt{(-1)*5}\\\sqrt{(-1)}=i\\x=^+_-i\sqrt{5}\\\\b)-x^2+49=0\\-x^2=-49\\(-x^2=-49)*(-1)\\x^2=49\\x=^+_-\sqrt{49}\\x=^+_-7\\\\c)x^2-9x+14=0\\ \Delta=(-9)^2-4*1*14\\\Delta=81-56\\\Delta=25\\\\x=\frac{9^+_-5}{2}=\\x'=7\\x"=2$