Question

Considere a função f(x) = 1/|x-2| . O valor de f(-1/3) é: * A) -2/7 B) 7/3 C) -3/7 D) 3/7 E) 1/7

Answer 1

$\sf f(x) = \dfrac{1}{ \mid {x-2} \mid}$

• Dado uma função f(x), para determinar o valor de f(−1/3) deve-se substituir x por −1/3.

$\sf f \left( -\dfrac{1}{3} \right) = \dfrac{1} { \left| {-\dfrac{1}{3}-2} \right| }$

$\sf f \left( -\dfrac{1}{3} \right) = \dfrac{1} { \left| {\dfrac{-1-6}{3}} \right| }$

$\sf f \left( -\dfrac{1}{3} \right) = \dfrac{1} { \left| {-\dfrac{7}{3}} \right| }$

$\sf f \left( -\dfrac{1}{3} \right) = \dfrac{~~1~~} {\dfrac{7}{3}}$

$\Large \sf f \left( -\frac{1}{3} \right) = \dfrac{3} {7}$

Resposta: Alternativa D.