show with a suitable example, that the sum of two monic polynomials need not to be a monic.
Answers
Answer:
What is a univariate polynomial?
A univariate polynomial is a polynomial that only has one variable.
These are all univariate polynomials:
x³ + 3x² + 7x - 15 → x is the only variable
2y² - 14y + 13 → y is the only variable
a³ + a² + a + 1 → a is the only variable
This is NOT a univariate polynomial:
x² - y² → it has two variables, x and y
What is a monic polynomial?
A monic polynomial
has only one variable (a univariate polynomial)
the nonzero coefficient of the highest degree term is equal to 1.
These are both monic polynomials
x² + 7x + 14 → variable x → leading coefficient 1
y² + 8y- 28 → variable y → leading coefficient 1
These are NOT monic polynomials:
x² + y² → two variables
2x³ + x² + x + 1 → leading coefficient is 2
Must the sum of two monic polynomials always be monic?
Let’s add the two monic polynomials from above:
x² + 7x + 14
y² + 8y – 28
——————————
x² + y² + 7x + 8y – 14
This is NOT monic because it has two variables