Question

已知f(x)=x^2-1,g(x)=x-1(x<0),g(x)=2-x(x>0).求f(g(x))与g(f(x)).

已知f(x)=x^2-1,g(x)=x-1(x<0),g(x)=2-x(x>0).求f(g(x))与g(f(x)).

Answer 1

x^2-2x (x<0)
f(g(x))=
x^2-4x=3 (x>0)

x^2-2 (x<0)
g(f(x))=
-x^2+3 (x>0)