As shown in figure above, for a function
f:X→Y
, each element x in the domain X has a unique image y in the codomain Y.
The function can be written as:
y=f(x)orf:x↦f(x)
- For y=f(x) , we say y is a function of x.
- f(x) is also called the value of the function f at x.
- f(x) is read as "f of x".
Example:
Given the function f:x↦5x+1 , find the value of
a. f(2)
b. f(−3)
c. f(25)
Answer:
(a)
f(x)=5x+1f(2)=5(2)+1=11
(b)
f(x)=5x+1f(−3)=5(−3)+1=−14
(c)
f(x)=5x+1f(25)=5(25)+1=3
Given the function f:x↦5x+1 , find the value of
a. f(2)
b. f(−3)
c. f(25)
Answer:
(a)
f(x)=5x+1f(2)=5(2)+1=11
(b)
f(x)=5x+1f(−3)=5(−3)+1=−14
(c)
f(x)=5x+1f(25)=5(25)+1=3