Question

Considerando que f(x) = 2x − 4 e g(x) = x 2 + 2x − 2, calcule:
(a) O valor de f(x) e g(x) para x = 4.
(b) O resultado de: [f(1) . g(1)]
(c) O resultado de: f(2) + 2 . g(2)

Answer 1

F ( x ) = 2 x - 4
G ( x ) = x² + 2 x - 2
______________________________

F ( 4 ) = 2 * 4 - 4
F ( 4 ) = 8 - 4
F ( 4 ) = 4

G ( 4 ) = 4² + 2 * 4 - 2
G ( 4 ) = 16 + 8 - 2
G ( 4 ) = 16 + 6 = 22
______________________________
F ( 1 ) = 2 * 1 - 4 = 2 - 4 = - 2
G ( 1 ) = 1² + 2 * 1 - 2 = 1 + 2 - 2 = 1

[ - 2 * 1 ] = - 2
______________________________
F ( 2 ) = 2 * 2 - 4 = 4 - 4 = 0
G ( 2 ) = 2² + 2 * 2 - 2 = 4 + 4 - 2 = 8 - 2 = 6

0 + 2 * 6 = 0 + 12 = 12

Answer 2

Boa tarde Valentina

f(x) = 2x - 4 
g(x) = x² + 2x - 2

a) 

f(4) = 2*4 - 4 = 8 - 4 = 4 
g(4) = 4² + 2*4 - 2 = 16 + 8 - 2 = 22 

b)

f(1) = 2*1 - 4 = 2 - 4 = -2 
g(1) = 1² + 2*1 - 2 = 1 + 2 - 2 = 1

f(1)*g(1) = -2*1 = -2

c)

f(2) = 2*2 - 4 = 0 
g(2) = 2² + 2*2 - 2 = 4 + 4 - 2 = 6

f(2) + 2*g(2) = 0 + 2*6 = 12

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