A power function is of the form xa where a is a real number. A polynomial function is of the form anxn + an-1xn-1 + ... + a1x + a0 for some positive integer n, and all the ai are real constants.
A rational function is the quotient of two polynomial functions.
Such functions are defined as one polynomial divided by another polynomial. Their properties include that they are defined at all points, except when the denominator is zero. Also, such functions are continuous at all points where they are defined; and all their derivatives exist at any point where they are defined.For more details, I suggest you read the Wikipedia article - or some other source - on "Rational function".
As with most advanced math, if your "real life" involves engineering work, you will use such math; otherwise, you will hardly have anything to do, in this case, with polynomial functions.
Basically, an expression is not a polynomial when anything is done that is not allowed in a polynomial - for example, use any variable in the denominator of a monomial, use non-integral powers or radicals (which is basically the same as a non-integral power), use functions, etc.
Substitute that value of the variable and evaluate the polynomial.
Yes, all polynomial functions are continuous.
That depends on what you mean with "real-life". You won't need polynomial functions to sell stuff at a supermarket, or to cut off a dead branch from your tree... but if you work in science and engineering, you will need some really advanced math - much more than a simple polynomial function.
In the 1880s, Poincaré created functions which give the solution to the order polynomial equation to the order of the polynomial equation
None, except that they are functions of one or more variables.
A power function is of the form xa where a is a real number. A polynomial function is of the form anxn + an-1xn-1 + ... + a1x + a0 for some positive integer n, and all the ai are real constants.
1 2 3 and 4 are 4 numbers, they are not functions of any sort - cubic polynomial or otherwise.
A rational function is the quotient of two polynomial functions.
That's the definition of a "rational function". You simply divide a polynomial by another polynomial. The result is called a "rational function".
A device that was designed to tabulate polynomial functions
You set x = 0 and evaluate the polynomial. Note that this should be "y-intercept" in the singular, not in the plural.
Such functions are defined as one polynomial divided by another polynomial. Their properties include that they are defined at all points, except when the denominator is zero. Also, such functions are continuous at all points where they are defined; and all their derivatives exist at any point where they are defined.For more details, I suggest you read the Wikipedia article - or some other source - on "Rational function".