Question

1-
f(x)=x2-5x+4 calcule:

A) f(1)

B) f(2)

C) f(-1)

D) f(x)=0

2-
f(x)=2x2-1

A) f(0)

B) f(5)

C) f(-3)

D) f(-5)​

Answer 1

Resposta:

F(x)= x²-5x+4

A) F(1)= 1²-5.1+4

F(1)= 1-5+4

F(1)= -4+4

F(1)=0

B) F(2)= 2²-5.2+4

D(2)= 4-10+4

F(2)= -6+4

F(2)= -2

C) F(-1)= (-1)²-5.(-1)+4

F(-1)= 1+5+4

F(-1)= 6+4

F(-1)= 10

D) F(x)= x²-5x+4=0

Δ= (-5)²-4.1.4

Δ= 25-16

Δ= 9

-b+√Δ

2a

-(-5)+√9

2.1

+5±3

2

primeira resposta 5+3/2= 8/2= 4

Segunda respira 5-3/2= 2/2= 1

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2) F(x)= 2x²-1

a) F(0)= 2.0²-1

F(0)= 2.0-1

F(0)= 0-1

F(0)= -1

B) F(5)= 2.5²-1

F(5)= 2.25-1

F(5)= 50-1

F(5)= 49

C) F(-3)= 2.(-3)²-1

F(-3)= 2.9-1

F(3)= 18-1

F(3)= 17

D) F(-5)= 2.(-5)²-1

F(-5)= 2.25-1

F(x)= 50-1

F(x)= 49