diketahui f(x) = 2x² + 3x dan g (x) = 5x + 4. tentukan a.(f°g) (x) =
b.(g°f) (x) =![]()
b.(g°f) (x) =
Jawab:
komposisi
f(x) = 2x² + 3x
g(x) = 5x + 4
a. fog(x) =
= f {g(x)}
= 2. (g(x))² + 3. g(x)
= 2 (5x + 4)² + 3 (5x +4)
= 2 (25x² + 40x + 16) + 15x + 12
= 50x²+80x + 32 + 15x + 12
= 50x² + 95 x + 44
b. (gof)(x) =
= g{ f(x)}
= 5. f(x) + 4
= 5(2x² +3x) + 4
= 10x² + 15x + 4
