Question

Jika f(x) = x - 5 dan g(x) = x2 - 1. tentukan fungsi fungsi berikut serta daerah asalnya!
a. 3f(x)
b. f(x) + g(x)
c. f(x) - g(x)
d. f(x) . g(x)
e. f(x) / g(x)
f. 3f(x) + (g(x))2

Answer 1

F(x) = x-5
g(x) = x²-1

a. 3f(x) = 3(x-5)
= 3x-15

b. f(x)+g(x) = (x-5)+(x²-1)
= x-5+x²-1
= x²+x-5-1
= x²+x-6

c. f(x)-g(x) = (x-5)-(x²-1)
= x-5-x²+1
= -x²+x-5+1
= -x²+x-4

d. f(x) . g(x) = (x-5)(x²-1)
= x³-x-5x²+5
= x³-5x²-x+5

e. f(x) / g(x) = x-5 / (x²-1)
= -5 / x-1

f. 3f(x) + (g(x))2 = 3(x-5) + (x²-1)2
= 3x-15 + 2x²-2
= 2x²+3x-15-2
= 2x²+3x-17