Answer:
(a)f(x)=x⁴+3x²
Explanation:
Part A
A polynomial in the fourth degree is any polynomial in which the highest power is 4.
An example of a fourth-degree polynomial with two terms is given below:
We know that this polynomial is in standard form since it is written in descending powers of x.
Part B
The closure property as it relates to the subtraction of polynomials tells us that when two polynomials are subtracted, one from the other, the result is always a polynomial.
Consider the polynomials, f(x) and g(x) below:
Subtracting f(x) from g(x):
Observe that the result is also a polynomial, hence the closure property applies.