Question

Seja a função f(x)= x^2-2x+8, calcule:
A) f(2)
B) f(-3)
C) f(-1) + f(2)
D) f(3) - f(-2)

Answer 1

f(x)= x²-2x+8

a) f(2)= 2²-2.2+8= 4-4+8= +8

b) f(-3)= (-3)²-2.(-3)+8= 9+6+8= 15+8=23

c) f(-1)= (-1)²-2.(-1)+8= 1+2+8= 11
f(-1)+f(2)= 11+8= 19

d)f(3)= 3²-2.3+8= 9-6+8= 3+8= 11
f(-2)= (-2)²-2.(-2)+8= 4+4+8= 8+8=16

f(3)-f(-2)= 11 -16= -5