Question

Dada f(2)= - 2 e f(1)=1 determine:

Answer 1

a)

f(x) = ax + b

f(2) = -2 x = 2 e y = - 2
2a + b = - 2

f(1) = 1 x = 1 e y = 1
a + b = 1

juntando as duas equacoes
{2a + b = - 2
{a + b = 1 *(-1)
‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
2a + b = - 2
- a - b = - 1
‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
a = - 3

a + b = 1
- 3 + b = 1
b = 1 + 3
b = 4

a funcao será:
f(x) = -3x + 4

b)
f(x) = -3x + 4
f(-3) = -3.(-3) + 4
f(-3) = 9 + 4
f(-3) = 13

c)
f(x) = -3x + 4
-3x + 4 = 0
-3x = - 4
x = -4/-3
x = 4/3

d)
coef. linear → b = 4
coef. angular → a = - 3

Espero ter ajudado