Question

Dada a função f(x) =2x²-9x+4 determine:
A)f(-2)
B)f(3)
C)f(-1)
D)f(0)

Answer 1

Vamos lá .

a) f(-2) :

f(x) = 2x²-9x+4

f(-2) = 2.(-2)² - 9.(-2) + 4

f(-2) = 2.4 + 18 + 4

f(-2) = 8+18+4 

f(-2) = 30

b) f(3) :

f(3) = 2.3² - 9.3 + 4

f(3) = 2.9 - 27 + 4

f(3) = 18-27+4

f(3) = -5

c) f(-1) :

f(-1) = 2.(-1)² - 9.(-1) + 4

f(-1) = 2.1 + 9 + 4

f(-1) = 2+9+4

f(-1) = 15

d) f(0) :

f(0) = 2.0² - 9.0 + 4

f(0) = 0+0+4

f(0) = 4