Question

me ajude e urgente !!!

consider f(x)=5x+2 e g(x)=x(ao quadrado)-2x+1 calcule:

  a)fog(-1)
b)gof(-2) 

Answer 1

Olá,  Loueslenne.

$f(x)=5x+2,g(x)=x^2-2x+1\Rightarrow\\\\f\circ g(x)=5g(x)+2=5x^2-10x+7\\\\ g\circ f(x)=[f(x)]^2-2f(x)+1=(5x+2)^2-2 (5x+2)+1$

Portanto:

$f\circ g(-1)=5+10+7=22\\\\ g\circ f(x)=(-10+2)^2-2 (-10+2)+1=\\\\=64+16+1=81$