Question

Dada a função de y=x²-7x+10 determine as raízes dessa função
A)2e-5.

B)5e2.
C)-2e5.
D)-2e-5

Answer 1

• $\underbrace{\small{y=x^{2}-7x+10}}$

▶️ Identificar os coeficientes

• $\small{a=\:\:1}$

• $\small{b=-7}$

• $\small{c=10}$

▶️ Encontrar o discriminante

• $\small{\Delta=b^{2}-4.a.c}$

• $\small{\Delta=(-7)^{2}-4.(1).(10)}$

• $\small{\Delta=49-40}$

• $\small{\Delta=9}$

▶️ Encontrar as raízes

• $\small{x'=\dfrac{[-(-7)+\sqrt{9}]}{2.(1)}}$

• $\small{x'=\dfrac{[7+3]}{2}}$

• $\small{x'=\dfrac{10}{2}}$

• $\underbrace{\small{x'=5}}$

• $\small{x"=\dfrac{[-(-7)-\sqrt{9}]}{2.(1)}}$

• $\small{x"=\dfrac{[7-3]}{2}}$

• $\small{x"=\dfrac{4}{2}}$

• $\underbrace{\small{x"=2}}$

▶️As raízes serão: 2 e 5