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Are trinomials and quadratics the same thing?

Hi, just confused on trinomials and quadratic equations.

A trinomial is an algebraic expression consisting of three terms.

A quadratic must have an x^2 in to be a quadratic right? So they are not the same?

Just need a clearer explanation as I'm confused :s-smilie:.
I don't think they are x^7 + 3x^5 + 3 is a trinomial, not a quadratic

x^2 + 5 is a quadratic but not a trinomial
(edited 8 years ago)
Reply 2
A quadratic is a function of x2 and x.

Haven't heard of a 'trinomial' before but with that definition it could encompass anything like x4 + 3x3 - x = 0 could it not? Which definitely isn't a quadratic.
Polynomial is of the form anxn+an1xn1+...+a1x+a0, an0\displaystyle a_nx^n+a_{n-1}x^{n-1}+...+a_1x+a_0,~a_n \neq 0

Trinomial is a polynomial consisting of three terms.

Quadratic is a polynomial with highest degree of 2.

Example: x^50+x^4+1 is a trinomial. (Since it is a polynomial with 3 terms)

x^2+2x is a quadratic. (Since it has highest degree 2)

x^2+4x+4 (is both a trinomal and a quadratic)

x^3+4x^2 is neither.
Original post by Dinasaurus
I don't think they are x^7 + 3x^-5 + 3 is a trinomial, not a quadratic

x^2 + 5 is a quadratic but not a trinomial


I don't think it would be would it, since it's not even a polynomial so it is automatically not a trinomial.
Reply 5
Original post by poorform
Polynomial is of the form anxn+an1xn1+...+a1x+a0, an0\displaystyle a_nx^n+a_{n-1}x^{n-1}+...+a_1x+a_0,~a_n \neq 0

Trinomial is a polynomial consisting of three terms.

Quadratic is a polynomial with highest degree of 2.

Example: x^50+x^4+1 is a trinomial. (Since it is a polynomial with 3 terms)

x^2+2x is a quadratic. (Since it has highest degree 2)

x^2+4x+4 (is both a trinomal and a quadratic)

x^3+4x^2 is neither.


Thank you, that makes perfect sense :smile:.
Original post by marcus888
Thank you, that makes perfect sense :smile:.


You're welcome :smile:

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