Question

-x^2+2x+8=0 determine a função quadratica

Answer 1

-x² + 2x + 8 = 0

a = -1; b = 2; c = 8

x = [- b ± √(b² - 4ac)] / 2a
x = [- 2 ± √(2² - 4 . [-1] . 8)] / 2 . (-1)
x = [- 2 ± √(4 + 32)] / -2
x = [- 2 ± √36] / -2
x = [- 2 ± 6] / -2
x' = [- 2 + 6] / -2 = 4 / -2 = -2
x'' = [- 2 - 6] / -2 = -8 / -2 = 4

S = {-2, 4}

Espero ter ajudado. Valeu!