Question

data a equação
$x ^{2} - x - 15 = 0$
determine
$b {}^{2} - 4ac$

Answer 1

$b^{2} - 4.a.c$ = Δ

$x^{2} - x - 15 = 0$

a = 1

b = -1

c = -15

Δ = $b^{2} - 4.a.c$ = (1)² - (4.-1.-15)

$b^{2} - 4.a.c$ = 1 - 60

$b^{2} - 4.a.c$ = -59