Question

dada a funçao f(x)= -2x²+2x, o valor de f(-1) +f(0) + f(1) e ???

a -4
b 0
c 1
d 4

Answer 1

Olá!

$f(x) = -2x^2 + 2x \\ \\ f(-1) + f(0) + f(1) = ? \\ \\ \Leftrightarrow f(-1) = ? \\ \Leftrightarrow f(-1) -2(-1)^2 + 2(-1) \\ \Leftrightarrow f(-1) = -2.1 -2 \\ \Leftrightarrow f(-1) = -2 -2 \\ \Leftrightarrow f(-1) = -4 \\ \\ f(0) = ? \\ \Leftrightarrow f(0) = -2.0^2 + 2.0 \\ \Leftrightarrow f(0) = \cancel{-2.0} + \cancel{2.0} \\ \Leftrightarrow f(0) = 0 \\ \\ \Leftrightarrow f(1) = ? \\ \Leftrightarrow f(1) = -2.1^2 + 2.1 \\ \Leftrightarrow f(1) = -2.1 + 2 \\ f(1) = -2 + 2 \\ f(1) = 0$

$f(-1) + f(0) + f(1) = -4 + 0 + 0 \\ f(-1) + f(0) + f(1) = -4$

$\textbf{Alternativa Correcta: A}$

$\textbf{Bons estudos.}$