Question

seja a funcao f: D> IR dada por f(x) = 2x + 1, determine: a) f(2)= b) f(-2)= c) f(0)= d) f(1)

Answer 1

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

$\large\begin{array}{lr}\sf f(x)= 2x+4\left\{\begin{array}{ll}\sf x\rightarrow 2\\\sf x \rightarrow -2\\\sf x \rightarrow 0 \\\sf x \rightarrow 1\end{array}\right.\end{array}$

Primeiramente iremos encontrar o f(2).

$\large\begin{array}{lr}\sf f(x)= 2x+1 \\\\\sf f(2) = 2(2)+1\\\\\sf f(2) = 4+1\\\\\sf f(2) = \underline{\boxed{\red{\sf 5}}}\end{array}$

Agora devemos encontrar o f(-2).

$\large\begin{array}{lr}\sf f(x)= 2x+1 \\\\\sf f(-2) = 2(-2)+1\\\\\sf f(-2) = -4+1\\\\\sf f(-2) = \underline{\boxed{\red{\sf -3}}}\end{array}$

Agora encontraremos o f(0).

$\large\begin{array}{lr}\sf f(x)= 2x+1 \\\\\sf f(0) = 2(0)+1\\\\\sf f(0) = 0+1\\\\\sf f(0) = \underline{\boxed{\red{\sf 1}}}\end{array}$

Por fim devemos encontrar o f(1).

$\large\begin{array}{lr}\sf f(1)= 2x+1 \\\\\sf f(1) = 2(1)+1\\\\\sf f(1) = 2+1\\\\\sf f(1) = \underline{\boxed{\red{\sf 3}}}\end{array}$

Concluirmos então que:

$\large\begin{array}{lr}\sf f(2) = \underline{\boxed{\red{\sf 5}}}\\\\\sf f(-2) = \underline{\boxed{\red{\sf -3}}}\\\\\sf f(0) = \underline{\boxed{\red{\sf 1}}}\\\\\sf f(1) = \underline{\boxed{\red{\sf 3}}}\end{array}$

Espero ter ajudado.

Bons estudos.

• Att. FireClassis.