Students can study about Rational functions and learn to solve problems related to them. Students can get help with Calculus problems involving Rational functions from the online tutors.

In mathematics, a rational functions is any functions which can be written as the ratio of two polynomial functions. In the case of one variable,a function is called a rational function if and only if it can be written in the form f(x) = (p(x)) / (q(x)

Where P and Q are polynomial functions in x and Q is not the zero polynomial. The domain of f is the set of all points for which the denominator Q(x) is not zero.

 

Solving Rational functions

 

Below is given few examples showing the way to Solving Rational functions:

An Example

Here is an example of a rational functions: f ( x ) = ( x2 + x – 20 ) / ( x2 – 3x – 18 )

Factored form :

f ( x ) =` (( x + 5 ) ( x - 4 )) / (( x + 3 ) ( x - 6 ))`The square roots of the denominator are clearly x = -3 and x = 6. If x gets on either of these two values, the denominator happens to equal to zero. While one can not divide by zero, the functions are not defined for these two values of x. We declare that the functions is discontinuous at x = -3 and x = 6.

The domain for the functions, ( - ∞, - 3 ) U ( - 3, 6 ) U ( 6, + ∞ )

 

Polynomial and rational functions

 

The x-intercepts of the rational function: The x-intercepts for this function can be where the output, or y-value, equals zero. It is equal to zero when the numerator is equal to zero. The roots of the numerator polynomial are x = -5 and x = 4.When x gets on either of these two values the numerator happens to zero, and the output of the function, or y-value, also turn into zero.So, therefore x-intercepts meant for this rational function are x = -5 and x = 4.

 

 

The y intercept of the Rational function: The y intercept for this function would be where the input, or x, value equals zero. If we seem at our first not factored form for this function,y = ( x2 + x – 20 ) / ( x2 – 3x – 18 )

putting x = 0 we get:

y = ( 02 + 0 – 20 ) / ( 02 – 3(0) – 18 )

y = `( - 20 ) / ( - 18 )`

y = `10 / 9 `        

y = 1.11

the y-intercept = 1.11 or (10/9) is simply for the two polynomials.