arithmetic combinations

Question

f(x) = x² + 1 and g(x) = x - 4

1) (f + g)(2)

2) (fg)(6)

3) (fg)(5) + f(4)

Answer 1

The concept of these problem is to evaluate the functions at the value provided, then perform the indicated operation.

Problem 1

f(2) = (2)²+1 = 5

g(2) = 2-4 = -2

Since the operation indicated is addition

5+-2 = 3

Problem 2

f(6) = (6)²+1 = 37

g(6) = 6-4 = 2

Since the operation indicated is multiplication

(37)(2) = 74

Problem 3

f(5) = (5)²+1 = 26

g(5) = 5-4 = 1

f(4) = (4)²+1 = 17

This is a combination of multiplication and addition.

(26)(1)+17 = 43