Question

Ditentukan oleh rumus f(x) = 2x-1dan g(x) = x (pangkt 2
tentukan:

nilai fungsi (f o g) (1) dan (f o g) (-2)

Answer 1

Cara smart :
(f o g) (1),  
x = 1
g(x) = x²
g(1) = 1² =1

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

g(-2) = (-2)²
         =  4

(f o g) (-2) = f(g(-2))
                  = 2x -1
                  = 2(4) -1
                  = 7
 

Answer 2

F(x) = 2x - 1
g(x) = x²

(fog)(x) = f(gx)
           = 2(x²) - 1
           = 2x² - 1

(fog)(1) = 2(1)² - 1
           = 2 - 1 = 1

(fog)(-2) = 2(-2)² - 1
            = 8 - 1 = 7