Question

calcule a coordenada do vertice f[x]=X2+4X-21

Answer 1

□OLÁ! TD BEM?

F(X) = X² + 4X - 21

Δ = B² - 4 a.c

Δ = 4² - 4 . 1 . (- 21)

Δ = 16 + 84

Δ = 100

$xv = \frac{ - b}{2 \times a} \\ xv = \frac{ - ( + 4)}{2 \times 1} \\ xv = \frac{ - 4}{2} \\ xv = - 2 \\ \\ yv = \frac{ - Δ}{4 \times a} \\ yv = \frac{ - ( + 1 00) }{4 \times 1} \\ yv = \frac{ - 100}{4} \\ yv = - 25$