Question

A cubic polynomial is a polynomial of degree
A. $1$
B. $2$
C. $3$
D. $4$

Answer 1

In the given question, we have to find out the degree of cubic polynomial. A cubic polynomial is that whose maximum power of the variable used in the equation is $3$; whereas a variable is that whose value varies or changes. For example, $x,y$; and constant is that whose value does not vary and remains the same, for example, $\pi = 3.14$.

Complete answer:
The given question is about the degree of cubic polynomials. Polynomials are nothing but the addition and subtraction of variables and constants arranged in an order where the power of these variables is different from one another and on the basis of the power of variables, polynomials are classified into various types.
First of all, the power of the variable should be checked; if the power of the variable is $1$, then the equation is classified as a linear equation or linear polynomial. So, option (A) is wrong and if the power of the variable is $2$, then the equation of the polynomial is classified as a quadratic equation or quadratic polynomial. So, the degree of quadratic polynomial is $2$. So, option (B) is wrong.
Now, if the power of a variable is $3$, then the equation of the polynomial is classified as a cubic equation or cubic polynomial. It means cubic polynomial is where the polynomial is having degree $3$ . Therefore, option (C) is correct because a cubic polynomial is a polynomial of degree $3$. The last option (D) which is saying that cubic polynomial is a polynomial of degree $4$ which is wrong because these types of equations or polynomials are treated as higher order of polynomials.

So, the correct answer is option C.

Note: In any polynomial, the power of variable should be a whole number. Power of variable cannot be negative, power of variable cannot be fraction, for example, $\dfrac{3}{4}$. Polynomials are classified as monomial, binomial and trinomial also on the basis of the number of variables used. For example, $x$ is the example of monomial, $\left( {2x + y} \right)$ is the example of binomial and $\left( {2x + 3y + 4z} \right)$ is the example of trinomial.