Question

jika f(x)=x(x+) maka tentukan

a.f(3+f(1)
b.f(5)-f(4)​

Answer 1

Given: f(x) = x (x + 3)

To find:

a. f(3) + f(1), b. f(5) - f(4)

Solution:

First we find the functional value at x = 3, x = 1, x = 5 and x = 4

• f(3) = 3 (3 + 3) = 3 (6) = 18
• f(1) = 1 (1 + 3) = 1 (4) = 4
• f(5) = 5 (5 + 3) = 5 (8) = 40
• f(4) = 4 (4 + 3) = 4 (7) = 28

• Now, f(3) + f(1) = 18 + 4 = 22
• and f(5) - f(4) = 40 - 28 = 12

Answer:

f(3) + f(1) = 22

f(5) - f(4) = 12