Question

considerando a função f(x)=x³+2x²+3x+4, calcule

a) f(2)
b) f(-2)
c) f(3)
d) f(-3)

Answer 1

f(x) = x³ + 2x² + 3x + 4

a) f(2) = (2)³ + 2(2)² + 3(2) + 4

f(2) = 8 + 2(4) + 6 + 4

f(2) = 8 + 8 + 6 + 4

f(2) = 26

b) f(-2) = (-2)³ + 2(-2)² + 3(-2) + 4

f(-2) = - 8 + 2(4) - 6 + 4

f(-2) = - 8 + 8 - 6 + 4

f(-2) = - 2

c) f(3) = (3)³ + 2(3)² + 3(3) + 4

f(3) = 27 + 2(9) + 9 + 4

f(3) = 27 + 18 + 9 +4

f(3) = 58

d) f(-3) = (-3)³ + 2(-3)² + 3(-3) + 4

f(-3) = - 27 + 2(9) - 9 + 4

f(-3) = - 27 + 18 - 9 + 4

f(-3) = - 14