Question

Sendo as funções f(x) =x²+1 e g(x) = 2x-1, de R em R , calcule (fog)(2):

( ) 7
( ) 9
( ) 8
( ) 10

Answer 1

Explicação passo-a-passo:

$\sf g(x)=2x-1$

• $\sf g(2)=2\cdot2-1$

$\sf g(2)=4-1$

$\sf g(2)=3$

Assim, $\sf f(g(2))=f(3)$

$\sf f(x)=x^2+1$

• $\sf f(3)=3^2+1$

$\sf f(3)=9+1$

$\sf f(3)=10$

Logo, $\sf f(g(2))=10$

Answer 2

Resposta:

10

Explicação passo-a-passo:

f(x) = x²+1 e g(x) = 2x-1

g(x) =2x-1

gf(x)=2(x²+1)-1

gf(2) = 2(2²+1)-1

gf(2) = 2(4+1)-1

gf(2) =2.5-1

gf(2) =10-1

gf(2) =9

f(x) = x²+1

fg(x) =(2x-1)²+1

fg(-2) = ((2.(-2)-1))²+1

fg(-2) = (-4-1)²+1

fg(-2) = (-5)²+1

fg(-2) =25+1

fg(-2)=26

g(x) = 2x-1

gg(x) =2(2x-1)-1

gg(1) = 2(2.1-1)-1

gg(1) =2(2-1)-1

gg(1) =2.1-1

gg(1)= 1