Question

F(x) = 4x + 21 dan g(x) = 3x - 8. invers dari (fog)(x) adalah ....

Answer 1

(fog) = 4(3x-8) + 21
      = 12x - 32 + 21
      = 12x - 11
(fog)^- = y = 12x - 11           catatan x = y
           = 12x = Y + 11
           = x = 

atau dengan cara

 f- = 

g- = 

f- o g- = ) - \frac{21}{4} [/tex]

          =  x = 

karena (fog)- = (f- o g-)
                      

Answer 2

F(x) = 4x + 21
g(x) = 3x - 8
maka
(fog)(x) = f(g(x))
(fog)(x) = 4(3x-8) + 21
(fog)(x) = 12x - 32 + 21
(fog)(x) = 12x - 11

(fog)^-1(x) = y
y = 12x - 11
12x = y + 11
x = y+11
       12
(fog)^-1(x) = x+11
                     12
ket : (fog)^-1(x) = invers (fog)(x)