Jika fog(x) = 2x-1 dan g(x) = x+1 maka f(3)=….

Diket :

fog(x) = 2x-1

g(x) = x+1

Ditanya : f (3)..?

Misal :

x+1 =a

x = a-1

Substitusi g (x) ke f (x)

fog(x) = 2x-1

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

f (x+1) = 2x-1

Masukan pemisalan

f (a) = 2 ( a-1) -1

f (a) = 2a-2-1

f (a) = 2a-3

Maka :

f (3) = 2.3 -3

= 3

Semoga bermanfaat ✌

Fog(x) = f(g(x))
= f(x+1) = 2x+1

f(3) = f(2+1) —> x=2
= 2(2)+1 = 5