Question

Diketahui f(x) = 2x + 1 dan g(x) = x² + 4. Nilai dari ( g o f ) (-1) adalah...

A. -3
B. -1
C. 1
D. 5
E. 13​

Answer 1

• f(x) = 2x + 1
• g(x) = x² + 4

(g o f)(x) = g(f(x))

(g o f)(x) = (2x + 1)² + 4

(g o f)(-1) = (2(-1) + 1)² + 4

(g o f)(-1) = (-2 + 1)² + 4

(g o f)(-1) = (-1)² + 4

(g o f)(-1) = 1 + 4

(g o f)(-1) = 5

• opsi D