Question

Diketahu f(x) = x(x+4) dan g(x) = -2 + √x+4 , dengan x≥ -4 dan xεR. Tentukanlah...
a.f(3)
b.(fog) (2)

Answer 1

Verified answer

Kelas 10 Matematika
Bab Fungsi Komposisi

a] f(3)
= 3 . (3 + 4)
= 3 . 7
= 21

b] (fog) (2) = ?

g(x) = -2 + √(x + 4)
g(2) = -2 + √(2 + 4)
g(2) = -2 + √6

f(x) = x (x + 4)
f(x) = x² + 4x

f(-2 + √6)
= (-2 + √6)² + 4 (-2 + √6)
= 4 - 4√6 + 6 - 8 + 4√6
= 2