Question

determine as raízes ou zero da função quadrática F (x) =x2-4x-5​

Answer 1

Função Quadrática

• Coeficientes:

$\large \sf \boxed{ \begin{array}{lr} \large \sf \: a = 1 \\\large \sf b = - 4 \\ \large \sf \: c = - 5 \end{array}}$

• Discriminante:

$\boxed{ \begin{array}{lr} \\ \large \sf \: \Delta = {b}^{2} - 4ac \\ \\\large \sf \: \Delta = {( - 4)}^{2} - 4 \cdot1 \cdot - 5 \\ \\\large \sf \: \Delta = 16 + 20 \\ \\ \boxed{ \blue{\large \sf \: \Delta = 36 }} \\ \: \end{array}}$

• Bhaskara:

$\boxed{ \begin{array}{lr} \\ \large \sf \: x = \dfrac{ - b \pm \: \sqrt{\Delta} }{2.a} \\ \\ \\ \large \sf \: x = \dfrac{ - ( - 4) \pm \: \sqrt{36} }{2.1} \\ \\ \\ \large \sf \: x = \dfrac{ 4\pm \: 6 }{2} \\ \: \end{array}}$

• Raízes:

$\large \sf \boxed{ \boxed{ \large \sf \: x_{1} = \dfrac{4 + 6}{2} = \boxed{ \sf \red{5}}}} \\ \\ \large \sf \boxed{ \boxed{ \large \sf \: x_{2} = \dfrac{4 - 6}{2} = \boxed{ \sf \red{ - 1}}}}$

➡️ Resposta:

• $\huge \boxed{ \boxed{ \huge \sf \: S = \{ 5,- 1\}}}$