Question

Determine os pontos de intersecção da parábola da função f(x) =x²-7x + 10, com o eixo das abscissas:

(A) (5,0) e (2,0)
(B) (0,5) e (0,2)
(C) (7,10) e (10,7)
(D) (10,0) e (4,0)
(E) (0,0) e (4,10)

Answer 1

☑️Igualando essa função a zero

• $\overbrace{\blue{x^{2}-7x+10=0}}$

.

• $\small{\Delta=b^{2}-4.a.c}$

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

• $\small{\Delta=49-40=9}$

.

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

• $\small{x'=\dfrac{[7+3]}{2}}$

• $\small{x'=\dfrac{10}{2}}$

• $\small{x'=5}$

.

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

• $\small{x"=\dfrac{[7-3]}{2}}$

• $\small{x"=\dfrac{4}{2}}$

• $\small{x"=2}$

☑️Esses pontos serão: (5,0) e (2,0)