RATIONAL FUNCTIONS
General Mathematics
RATIONAL FUNCTIONS
It is a function that can be written in the form of:
𝑓 𝑥 =
𝑁(𝑥)
𝐷(𝑥)
Wherein N(x) and D(x) are both polynomials; D(x) must not
be a zero polynomial
RATIONAL FUNCTIONS EXERCISE:
Determine whether the functions presented are
considered rational or not:
RATIONAL FUNCTIONS EXERCISE:
𝑓 𝑥 =
4𝑥 − 2𝑥
1
3
𝑥2 + 5𝑥 − 4
RATIONAL FUNCTIONS EXERCISE:
𝑓 𝑥 =
9𝑥2
+ 6𝑥 + 1
3𝑥 + 1
RATIONAL FUNCTIONS EXERCISE:
𝑓 𝑥 =
𝑥 + 1
𝑥2 + 1
RATIONAL FUNCTIONS
Domain: All real numbers except any x-values that make the
denominator equals to 0
Range: Inverse Functions, Asymptotes
ZEROES OF RATIONAL FUNCTIONS
Steps in Finding Zeroes of Rational Functions:
1. Factor the numerator and denominator of the rational
function completely (if possible)
2. Identify the restrictions of the rational function (values that
will make the denominator equal to zero)
3. Identify the values that makes the numerator equal to zero
NOTE: these values must not be a restriction
ACTIVITY:
Find the zeroes of the rational function:
𝑓 𝑥 =
𝑥2
+ 6𝑥 + 8
𝑥2 − 𝑥 − 6
ASSIGNMENT:
(ZEROES OF RATIONAL FUNCTIONS)
1. 𝑓 𝑥 =
𝑥2−𝑥−12
𝑥2 −9
2. 𝑓 𝑥 =
𝑥+2
𝑥2 −3𝑥+2
3. 𝑓 𝑥 =
𝑥2−5𝑥−4
𝑥2 −4𝑥−1
4. 𝑓 𝑥 =
𝑥−5
𝑥2 −25
5. 𝑓 𝑥 =
𝑥2−7𝑥+6
𝑥2 −6𝑥+5

General Mathematics - Rational Functions