Question

Diket f(x) =2×-1 ,g(x) =×2+4
Tentukan :
a.(fog)(x)
b.(gof)(x)
c.(fog)(1)
d.(gof)(-1)

Answer 1

Verified answer

Jawab
f(x) =  2x - 1
g(x) = x^2 + 4

a. fog(x) = f (g(x)) = f (x^2 + 4) = 2(x^2 +4) - 1
fog(x) = 2x^2  + 7

b. gof(x)  = g {(f(x)} = g(2x -1) = (2x-1)^2 + 4 = 4x^2-4x+ 1 + 4
gof(x) = 4x^2 - 4x + 5

c. fog(1) = 2(1)^2 +  7 = 2+7
fog(1) = 9

d. gof(-1) = 2(-1)^2 - 4(-1) + 5 = 2 + 4 + 5
gof(-1)= 11