Question

Quais as raízes(x’ e x”) da função : y = x² + x - 2 ? * *

x’ = -1 e x “ = 4

x’ = 2 e x “ = 4

x’ = 3 e x “ = -9

x’ = 1 e x “ = -2​

Answer 1

Resposta:

x'=1 e x''= -2

Explicação passo-a-passo:

$\displaystyle Aplicando~a~f\'{o}rmula~de~Bhaskara~para~x^{2}+1x-2=0~~e~comparando~com~(a)x^{2}+(b)x+(c)=0,~determinamos~os~coeficientes:~\\a=1{;}~b=1~e~c=-2\\\\C\'alculo~do~discriminante~(\Delta):&\\&~\Delta=(b)^{2}-4(a)(c)=(1)^{2}-4(1)(-2)=1-(-8)=9\\\\C\'alculo~das~raizes:&\\x^{'}=\frac{-(b)-\sqrt{\Delta}}{2(a)}=\frac{-(1)-\sqrt{9}}{2(1)}=\frac{-1-3}{2}=\frac{-4}{2}=-2\\\\x^{''}=\frac{-(b)+\sqrt{\Delta}}{2(a)}=\frac{-(1)+\sqrt{9}}{2(1)}=\frac{-1+3}{2}=\frac{2}{2}=1\\\\S=\{-2,~1\}$