trinomial

{{Short description|Polynomial that has three terms}}

{{About|mathematics|the use in taxonomy|Trinomial name|the use identifying archaeological sites in the United States|Smithsonian trinomial}}

File:Pascal_pyramid_trinomial.svg derived from coefficients in an upside-down ternary plot of the terms in the expansions of the powers of a trinomial ]]

In elementary algebra, a trinomial is a polynomial consisting of three terms or monomials.{{cite web |url=https://www.mathsisfun.com/definitions/trinomial.html | title=Definition of Trinomial | work=Math Is Fun | accessdate=16 April 2016}}

Examples of trinomial expressions

  1. 3x + 5y + 8z with x, y, z variables
  2. 3t + 9s^2 + 3y^3 with t, s, y variables
  3. 3ts + 9t + 5s with t, s variables
  4. ax^2+bx+c, the quadratic polynomial in standard form with a,b,c variables.Quadratic expressions are not always trinomials, the expressions' appearance can vary.
  5. A x^a y^b z^c + B t + C s with x, y, z, t, s variables, a, b, c nonnegative integers and A, B, C any constants.
  6. Px^a + Qx^b + Rx^c where x is variable and constants a, b, c are nonnegative integers and P, Q, R any constants.

Trinomial equation

A trinomial equation is a polynomial equation involving three terms. An example is the equation x = q + x^m studied by Johann Heinrich Lambert in the 18th century.{{cite journal |first=R. M. |last=Corless |first2=G. H. |last2=Gonnet |first3=D. E. G. |last3=Hare |first4=D. J. |last4=Jerey |first5=D. E. |last5=Knuth |year=1996 |url=http://www.cs.uwaterloo.ca/research/tr/1993/03/W.pdf |title=On the Lambert W Function |journal=Advances in Computational Mathematics |volume=5 |issue=1 |pages=329–359 |doi=10.1007/BF02124750 }}

=Some notable trinomials =

  • The quadratic trinomial in standard form (as from above):

:: ax^2+bx+c

:: a^3 \pm b^3 = (a \pm b)(a^2 \mp ab + b^2)

  • A special type of trinomial can be factored in a manner similar to quadratics since it can be viewed as a quadratic in a new variable ({{math|xn}} below). This form is factored as:

:: x^{2n} + rx^n + s = (x^n + a_1)(x^n + a_2),

:where

:: \begin{align}

a_1+a_2 &= r\\

a_1 \cdot a_2 &= s.

\end{align}

:For instance, the polynomial {{math|x2 + 3x + 2}} is an example of this type of trinomial with {{math|1=n = 1}}. The solution {{math|1=a1 = −2}} and {{math|1=a2 = −1}} of the above system gives the trinomial factorization:

::{{math|1=x2 + 3x + 2 = (x + a1)(x + a2) = (x + 2)(x + 1)}}.

:The same result can be provided by Ruffini's rule, but with a more complex and time-consuming process.

See also

Notes

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References

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{{polynomials}}

Category:Elementary algebra

Category:Polynomials

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