jika f(x)= 3x+2 dan g(x)= -x ,tentukan a.fog. b.gof c.fof d.gog

fog= f(g(x))= 3(g(x)+2
                  = 3(-x)+2= -3x+2

gof= g(f(x))= -(f(x))
                  = -(3x+2)=-3x-2

fof= f(f(x))= 3(f(x))+2
                = 3(3x+2)+2 = 9x+6+2 = 9x+8

gog=g(g(x))= -(g(x))
                   = -(-x)= x

a)
(f○g)(x)
= f(g(x))
= f(-x)
= 3(-x) + 2
= - 3x + 2

b)
(g○f)(x)
= g(f(x))
= g(3x + 2)
= - (3x + 2)
= - 3x - 2

c)
(f○f)(x)
= f(f(x))
= f(3x + 2)
= 3(3x + 2) + 2
= 9x + 6 + 2
= 9x + 8

d)
(g○g)(x)
= g(g(x))
= g(- x)
= - (- x)
= x