Question

Determine o zero da função quadratica de -x2 + 2x +8

Answer 1

a= -2
b=2
c= 8
se utilizarmos a fórmula resolvente teremos :


x= ((-b) +- √b²-4ac) ÷ 2a
x =( -2 +- √4 - 4×(-2)×8 ) ÷ ( 2× (-2) )
x= ( -2 +- √68) ÷ (-4)
x = (-2 - 2√17) ÷ (-4) ∨ x = ( -2 + 2√17) ÷ (-4)
x= ( 1 + √17) ÷ 2 ∨ x = ( 1 - √17) ÷ 2