Jika fungsi f(x) = √x^2+1 dan (f o g)(x) = √x^2+2x+2, 9(X— 1) adalah ....

a. x
b. x+1
c. 1/x
d. 1/x-1
e. 1/x+1

Jika fungsi f(x) = √x^2+1 dan (f o g)(x) = √x^2+2x+2, 9(X— 1) adalah ….

Diketahui :
f(x) = $sqrt{ {x}^{2} : + : 1 }$
(f o g)(x) = $sqrt{ {x}^{2} : + : 2x : + : 2 }$

Ditanya :
g(x – 1)?

Jawab :
(f o g)(x) = f(g(x))
$sqrt{ {x}^{2} : + : 2x : + : 2 }$ = $sqrt{ ({g(x)})^{2} : + : 1 }$
x² + 2x + 1 = (g(x))²
g(x) = $sqrt{ {x}^{2} : + : 2x : + : 1 }$
g(x) = x + 1

g(x) = x + 1
g(x – 1) = (x – 1) + 1
g(x – 1) = x (A)