Question

1°)dada a explicação F(X)=2X+4
a)F(2)
b)F(-2)
c)F(3)+F(-3)
d)F(0)-F(3)+F(-3)​

Answer 1

Para calcular qualquer função que seja, basta alterarmos o valor dado pela incógnita x na função geral.

$\large\begin{array}{lr}\sf f(x)= 2x+4\left\{\begin{array}{ll}\sf x\rightarrow 2\\\sf x \rightarrow -2\\\sf x \rightarrow 3 \\\sf x \rightarrow -3\\\sf x \rightarrow 0\end{array}\right.\end{array}$

Primeiramente iremos encontrar o f(2).

$\large\begin{array}{lr}\sf f(x)= 2x+4 \\\\\sf f(2) = 2(2)+4\\\\\sf f(2) = 4+4\\\\\sf f(2) = \underline{\boxed{\red{\sf 8}}}\end{array}$

Agora devemos encontrar o valor de f(-2).

$\large\begin{array}{lr}\sf f(x)= 2x+4 \\\\\sf f(-2) = 2(-2)+4\\\\\sf f(-2) = -4+4\\\\\sf f(-2) = \underline{\boxed{\red{\sf 0}}}\end{array}$

Agora devemos encontrar o valor de f(3) e de f(-3).

$\large\begin{array}{lr}\sf f(x)= 2x+4 \\\\\sf f(3) = 2(3)+4\\\\\sf f(3) = 6+4\\\\\sf f(3) = \underline{\boxed{\red{\sf 10}}}\end{array}$

$\large\begin{array}{lr}\sf f(x)= 2x+4 \\\\\sf f(-3) = 2(-3)+4\\\\\sf f(-3) = -6+4\\\\\sf f(-3) = \underline{\boxed{\red{\sf 2}}}\end{array}$

A questão pede a soma de f(3) com o f(-3) então:

$\large\begin{array}{lr}\sf f(3) + f(-3)=\\\\\sf 10 +2=\\\\ = \underline{\boxed{\red{\sf 12}}}\end{array}$

Agora devemos encontrar o f(0).

$\large\begin{array}{lr}\sf f(x)= 2x+4 \\\\\sf f(0) = 2(0)+4\\\\\sf f(0) = 0+4\\\\\sf f(0) = \underline{\boxed{\red{\sf 4}}}\end{array}$

f(0) - f(3) + f(-3).

$\large\begin{array}{lr}\sf f(0)-f(3) + f(-3)=\\\\\sf 0 - 10+2=\\\\ = \underline{\boxed{\red{\sf -8}}}\end{array}$

Concluirmos então que:

a) F(2) =>  $\underline{\boxed{\red{\sf 8}}}$

b) F(-2) => $\underline{\boxed{\red{\sf 0}}}$

c) F(3)+F(-3) => $\underline{\boxed{\red{\sf 12}}}$

d) F(0)-F(3)+F(-3) =>  $\underline{\boxed{\red{\sf -8}}}$

Espero ter ajudado.

Bons estudos.

• Att. FireClassis.