Question

1. Determine o valor de f(5), f(-1), f(2), f(0), f(-3), sendo f(x) = 2x − 5

2. Dada as funções f(x) = 2x – 3 e g(x) = 4 – x, determine:
a) f(–1)
b) f(x + 1)
c) g(4)
d) g(x – 2)

Answer 1

Questão 1)

$f(x)=2x-5\\ \\ f(5)=2\cdot5-5\\ \\ f(5)=10-5\\ \\ \boxed{f(5)=5}$

$f(x)=2x-5\\ \\ f(-1)=2\cdot(-1)-5\\ \\ f(-1)=-2-5\\ \\ \boxed{f(-1)=-7}$

$f(x)=2x-5\\ \\ f(2)=2\cdot2-5\\ \\ f(2)=4-5\\ \\ \boxed{f(2)=-1}$

$f(x)=2x-5\\ \\ f(0)=2\cdot0-5\\ \\ f(0)=0-5\\ \\ \boxed{f(0)=-5}$

$f(x)=2x-5\\ \\ f(-3)=2\cdot(-3)-5\\ \\ f(-3)=-6-5\\ \\ \boxed{f(-3)=-11}$

Questão 2)

Letra a)

$f(-1)~~~para~~~f(x)=2x-3\\ \\ f(-1)=2\cdot(-1)-3\\ \\ f(-1)=-2-3\\ \\ \boxed{f(-1)=-5}$

Letra b)

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

Letra c)

$g(4)~~~para~~~g(x)=4-x\\ \\ g(4)=4-4\\ \\ \boxed{g(4)=0}$

Letra d)

$g(x-2)~~~para~~~g(x)=4-x\\ \\ g(x-2)=4-(x-2)\\ \\ g(x-2)=4-x+2\\ \\ \boxed{g(x-2)=-x+6}$

:)