Question

determine os zeros da funcao y=x²+2x-3

Answer 1

 -x² + 2x + 3 = 0 

x² - 2x - 3 = 0 

[2 ± √(4 + 12)]/2 = 

(2 + √16)/2 = (2 + 4)/2 = 3 

(2 - √16)/2 = (2 - 4)/2 = -1

Answer 2

Δ=2.2-4.1.-3
Δ=4-4.-3
Δ=4+12
Δ=16

x=-2+-√16/2.a
x=-2+-4/2

x'=2+4/2=6/2=3
x''=2-4/2=-2/2=-1