Question

Marque as questões que defina uma função afim.
A) f(x) = x² - 5x B) f(x) = 2x + 3

C) f(x) = 3(x + 1) + 4(x - 1) D) f(x) = 5x + 2

E) f(x) = x² - 5x F) f(x) = (x + 2)² + 4

Answer 1

a) x ² - 5x = 0

   x(x - 5) = 0

   x = 0

b) f(x) = 2x - 3  

   f(-1) = 2 × (-1) - 3 = -2 - 3 = -5  

   f(0) = 2 × 0 - 3 = 0 - 3 = - 3  

   f(1) = 2 × 1 - 3 = 2 -3 = -1  

   f(2) = 2 × 2 - 3 = 4 -3 = 1

c) f(x) = 3(x+1) + 4(x-1)

   f(x) = 3x + 3 + 4x - 4

   f(x) = 3x + 4x + 3 - 4

   f(x) = 7x - 1

d)f(x) = 5x + 2

   f(x) = 0

   5x + 2 = 0

   5x = - 2

    x = - 2/5

e) x ² - 5x = 0

   x(x - 5) = 0

   x = 0

f) (x - 2)² = 4

(x - 2 ) ( x - 2) = 4

x² - 2x - 2x + 4 = 4

x² - 4x + 4 - 4 = 0

x² - 4x = 0

x ( x - 4 ) = 0

x = 0

x - 4 = 0

x = 4

x' = 0

x" = 4

S = { 0 e 4 }