Question

Dada a função afim f(x) = 2x + 3, determine A) f(-1) B) f(1/2)

Answer 1

Questão a)

Basta substituir  x  por  -1  na função.

$f(x)=2x+3~~~~para~~~~x=-1\\ \\ f(-1)=2\cdot(-1)+3\\ \\f(-1)=-2+3\\ \\ \boxed{f(-1)=1}$

Questão b)

$f(x)=2x+3~~~~para~~~~x=\dfrac{1}{2} \\ \\\\ f\left(\dfrac{1}{2} \right)=2\cdot\dfrac{1}{2} +3\\ \\\\ f\left(\dfrac{1}{2} \right)=-\dfrac{2}{2} +3\\ \\\\ f\left(\dfrac{1}{2} \right)=-1+3\\ \\ \\ \boxed{f\left(\dfrac{1}{2} \right)=2}$

:)