Question

Questão 7.
Dada a função real definida por f(x) = x - 3x, determine:
a) f(1)
b) f(-1)
c) f(3)​

Answer 1

Resposta:

a)

$f(1) = 1 - 3(1) = 1 - 3 = - 2$

b)

$f( - 1) = - 1 - 3( - 1) = - 1 + 3 = 2$

c)

$f(3) = 3 - 3( 3) = 3 - 9 = - 6$

Answer 2

f(x)=x-3x

a)f(1)=1-3×1

f(1)=1-3

f(1)=-2

b)f(-1)=-1-3×-1

f(-1)=-1+3

f(-1)=2

f(3)=3-3×3

f(3)=3-9

f(3)=-6

f(x)=x²-3x

f(1)=1²-3×1

f(1)=1-3

f(1)=-2

f(-1)=(-1)²-3×(-1)

f(1)=1+3

f(-1)=4

f(3)=3²-3×3

f(3)=9-9

f(3)=0