Question

dada a função, f(x)= -x²+5x+6,calcule
a) f (2)
b) x para f (x)=0
​

Answer 1

Explicação passo-a-passo:

a ) f ( x ) = - x2 + 5x + 6

f ( 2 ) = - ( 2 ) 2 + 5• 2 + 6

f ( 2 ) =. - 4 + 10 + 6

f ( 2 ) = 12

b) - x2 + 5x + 6 = 0

x2 - 5x - 6 = 0

∆ = (- 5 ) 2 - 4• 1 • ( - 6 )

∆ = 25 + 24

∆ = 49

X1 = ( 5 + 7 ) / 2

X1 = 12 / 2

X1 = 6

X2 = ( 5 - 7 ) / 2

X2 = - 2 / 2

X2 = - 1