How many zeros does a cubic polynomial have?

How many zeros does a cubic polynomial have?

Edited By Team Careers360 | Updated on Aug 02, 2023 09:49 AM IST

A polynomial is an algebraic expression consisting of variables and coefficients, combined using addition, subtraction, and multiplication, but not division by a variable. A cubic polynomial is a polynomial of degree three, which means that the highest power of the variable in the polynomial is three. The general form of a cubic polynomial is given by:

ax^3 + bx^2 + cx + d

where a, b, c, and d are constants and x is the variable.

The zeros or roots of a polynomial are the values of the variable that make the polynomial equal to zero. In other words, a zero or root of a polynomial is a solution to the equation obtained by setting the polynomial equal to zero. The zeros of a polynomial are also known as the x-intercepts or the solutions of the equation.

The number of zeros that a polynomial can have depends on its degree and coefficients. For a polynomial of degree n, there can be at most n zeros. However, not all of these zeros may be real or distinct, and some may be complex conjugate pairs.

Properties Of A Cubic Polynomial

The degree of a polynomial is the highest power of the variable that appears in the polynomial. In a cubic polynomial, the degree is three, which means that the highest power of the variable is x^3.

The leading coefficient of a polynomial is the coefficient of the term with the highest power of the variable. In a cubic polynomial of the form ax^3 + bx^2 + cx + d, the leading coefficient is a.

The relationship between the degree and number of zeros of a polynomial is given by the Fundamental Theorem of Algebra. According to this theorem, a polynomial of degree n has exactly n complex roots, counting multiplicity. This means that a cubic polynomial can have at most three roots or zeros, including complex conjugate pairs. However, the roots of a polynomial may not all be real or distinct, depending on the coefficients of the polynomial.

Maximum Number Of Zeros Of A Cubic Polynomial

The Fundamental Theorem of Algebra states that a polynomial of degree n has exactly n complex roots, counting multiplicity. This means that a cubic polynomial can have at most three roots or zeros, counting multiplicities. The zeros of a cubic polynomial can be either real or complex conjugate pairs.

The implication for a cubic polynomial is that it can have up to three zeros, but not more than three. This means that a cubic polynomial may have one, two, or three zeros, including complex roots.

An example of a cubic polynomial with three real zeros is:

f(x) = x^3 - 6x^2 + 11x - 6

To find the zeros of this polynomial, we can use the Rational Root Theorem or synthetic division to test for possible rational roots. In this case, we find that the polynomial has roots at x = 1, x = 2, and x = 3. Therefore, this cubic polynomial has three real roots, all of which are distinct.

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