COMPOSITION OF FUNCTIONS
General Mathematics
Learning Competencies:
 Defines composition of functions
 Performs composition of functions
 Evaluates functional problems using composition of
functions
Composition of Functions
 Operation of function that must have two functions
namely: f(x) and g(x), and then perform the indicated
operation to produce the result: h(x)
 Also defined as “applying a function to the other function”
Composition of Functions
𝑓 𝑥 = 3𝑥 − 1; 𝑔 𝑥 = 𝑥 + 4
𝐹𝑖𝑛𝑑 𝑓 ○ 𝑔
Composition of Functions
𝑓 𝑥 = 3𝑥 − 1; 𝑔 𝑥 = 𝑥 + 4
𝑓 ○ 𝑔 = 3 𝑥 + 4 − 1
𝑓 ○ 𝑔 = 3𝑥 + 12 − 1
𝑓 ○ 𝑔 = 3𝑥 + 11
EXERCISE!
DIRECTIONS: Evaluate the given composite functions
𝑓 𝑥 = 𝑥2
− 6; 𝑔 𝑥 = 𝑥 + 4
𝑓 𝑥 = 𝑥 + 3; 𝑔 𝑥 = 𝑥 − 9
𝑓 𝑥 = 2𝑥 + 4; 𝑔 𝑥 = 8 − 3𝑥
Composition of Functions
𝑓 𝑥 =
1
2
𝑥 − 4; 𝑔 𝑥 = 𝑥 + 3
𝐹𝑖𝑛𝑑 𝑓 ○ 𝑔
Composition of Functions
𝑓 𝑥 =
1
2
𝑥 − 4; 𝑔 𝑥 = 𝑥 + 3
f ○ 𝑔 =
1
2
𝑥 + 3 − 4
𝑓 ○ 𝑔 = 2
1
2
𝑥 + 3 − 4 2
𝑓 ○ 𝑔 = 𝑥 + 3 − 8
𝑓 ○ 𝑔 = 𝑥 − 5
Composition of Functions
𝑓 𝑥 =
2
𝑥 + 3
; 𝑔 𝑥 =
−3𝑥 − 2
𝑥
𝐹𝑖𝑛𝑑 𝑓 ○ 𝑔
Composition of Functions
𝑓 𝑥 = 4𝑥 + 3; 𝑔 𝑥 = 𝑥 − 2
𝐹𝑖𝑛𝑑 𝑓(𝑔 5 )
Composition of Functions
𝑓 𝑥 = 4𝑥 + 3; 𝑔 𝑥 = 𝑥 − 2
𝑓 𝑔 5 = 4 5 − 2 + 3
𝑓 𝑔 5 = 4 3 + 3
𝑓 𝑔 5 = 12 + 3
𝑓 𝑔 5 = 15
Composition of Functions
𝑓 𝑥 = 6𝑥 − 4; 𝑔 𝑥 = 𝑥 − 8
𝐹𝑖𝑛𝑑 𝑓(𝑔 9 )
Composition of Functions
𝑓 𝑥 = 6𝑥 − 4; 𝑔 𝑥 = 𝑥 − 8
𝑓 𝑔 9 = 6 9 − 8 − 4
𝑓 𝑔 9 = 6 1 − 4
𝑓 𝑔 9 = 6 − 4
𝑓 𝑔 9 = 2
EXERCISE!
DIRECTIONS: Evaluate the given composite functions
𝑓 𝑥 = 𝑥2
+ 7; 𝑔 𝑥 = 𝑥 − 3: 𝐹𝑖𝑛𝑑 𝑓(𝑔 3 )
𝑓 𝑥 = 𝑥 + 3; 𝑔 𝑥 = 𝑥 − 5: 𝐹𝑖𝑛𝑑 𝑔 ○ 𝑓
𝑓 𝑥 =
1
4
𝑥 + 6; 𝑔 𝑥 = 𝑥 + 4: 𝐹𝑖𝑛𝑑 𝑓 ○ 𝑔
𝑓 𝑥 = 7𝑥 + 4; 𝑔 𝑥 = 2𝑥 − 4: 𝐹𝑖𝑛𝑑 𝑔(𝑔 5 )

General Mathematics - Composition of Functions

  • 1.
  • 2.
    Learning Competencies:  Definescomposition of functions  Performs composition of functions  Evaluates functional problems using composition of functions
  • 3.
    Composition of Functions Operation of function that must have two functions namely: f(x) and g(x), and then perform the indicated operation to produce the result: h(x)  Also defined as “applying a function to the other function”
  • 5.
    Composition of Functions 𝑓𝑥 = 3𝑥 − 1; 𝑔 𝑥 = 𝑥 + 4 𝐹𝑖𝑛𝑑 𝑓 ○ 𝑔
  • 6.
    Composition of Functions 𝑓𝑥 = 3𝑥 − 1; 𝑔 𝑥 = 𝑥 + 4 𝑓 ○ 𝑔 = 3 𝑥 + 4 − 1 𝑓 ○ 𝑔 = 3𝑥 + 12 − 1 𝑓 ○ 𝑔 = 3𝑥 + 11
  • 7.
    EXERCISE! DIRECTIONS: Evaluate thegiven composite functions 𝑓 𝑥 = 𝑥2 − 6; 𝑔 𝑥 = 𝑥 + 4 𝑓 𝑥 = 𝑥 + 3; 𝑔 𝑥 = 𝑥 − 9 𝑓 𝑥 = 2𝑥 + 4; 𝑔 𝑥 = 8 − 3𝑥
  • 8.
    Composition of Functions 𝑓𝑥 = 1 2 𝑥 − 4; 𝑔 𝑥 = 𝑥 + 3 𝐹𝑖𝑛𝑑 𝑓 ○ 𝑔
  • 9.
    Composition of Functions 𝑓𝑥 = 1 2 𝑥 − 4; 𝑔 𝑥 = 𝑥 + 3 f ○ 𝑔 = 1 2 𝑥 + 3 − 4 𝑓 ○ 𝑔 = 2 1 2 𝑥 + 3 − 4 2 𝑓 ○ 𝑔 = 𝑥 + 3 − 8 𝑓 ○ 𝑔 = 𝑥 − 5
  • 10.
    Composition of Functions 𝑓𝑥 = 2 𝑥 + 3 ; 𝑔 𝑥 = −3𝑥 − 2 𝑥 𝐹𝑖𝑛𝑑 𝑓 ○ 𝑔
  • 12.
    Composition of Functions 𝑓𝑥 = 4𝑥 + 3; 𝑔 𝑥 = 𝑥 − 2 𝐹𝑖𝑛𝑑 𝑓(𝑔 5 )
  • 13.
    Composition of Functions 𝑓𝑥 = 4𝑥 + 3; 𝑔 𝑥 = 𝑥 − 2 𝑓 𝑔 5 = 4 5 − 2 + 3 𝑓 𝑔 5 = 4 3 + 3 𝑓 𝑔 5 = 12 + 3 𝑓 𝑔 5 = 15
  • 14.
    Composition of Functions 𝑓𝑥 = 6𝑥 − 4; 𝑔 𝑥 = 𝑥 − 8 𝐹𝑖𝑛𝑑 𝑓(𝑔 9 )
  • 15.
    Composition of Functions 𝑓𝑥 = 6𝑥 − 4; 𝑔 𝑥 = 𝑥 − 8 𝑓 𝑔 9 = 6 9 − 8 − 4 𝑓 𝑔 9 = 6 1 − 4 𝑓 𝑔 9 = 6 − 4 𝑓 𝑔 9 = 2
  • 16.
    EXERCISE! DIRECTIONS: Evaluate thegiven composite functions 𝑓 𝑥 = 𝑥2 + 7; 𝑔 𝑥 = 𝑥 − 3: 𝐹𝑖𝑛𝑑 𝑓(𝑔 3 ) 𝑓 𝑥 = 𝑥 + 3; 𝑔 𝑥 = 𝑥 − 5: 𝐹𝑖𝑛𝑑 𝑔 ○ 𝑓 𝑓 𝑥 = 1 4 𝑥 + 6; 𝑔 𝑥 = 𝑥 + 4: 𝐹𝑖𝑛𝑑 𝑓 ○ 𝑔 𝑓 𝑥 = 7𝑥 + 4; 𝑔 𝑥 = 2𝑥 − 4: 𝐹𝑖𝑛𝑑 𝑔(𝑔 5 )