Determine whether f(x) represents a polynomial function. If possible, identify the degree ad type of polynomial function.

Question

anonymous · Answer

$$f(x) = 8 - 9x^3$$

e.mccormick · Answer

OK, this comes down to the meaning of polynomeal, function, ad degree.  How are you with those?

anonymous · Answer

pretty good

e.mccormick · Answer

OK.  So, which parts of this one do you know, and which are you unsure about?

anonymous · Answer

So i believe this is a polynomial function with a degree of 3, but not sure of the last part.

e.mccormick · Answer

So the type.  Well, it has two terms, that can be used to name the type and it is a 3rd degree, which can also be used to name the type.  Any ideas on what thise two types would be?

anonymous · Answer

With two terms I believe it is quadratic

e.mccormick · Answer

Not quite.  A quadratic is 2nd degree.

e.mccormick · Answer

So you had a 2, but you picked the wrong 2 based definition.

anonymous · Answer

cubic?

e.mccormick · Answer

It is cubic.  The 3rd degree as highest means it is a cubic equation.  And because there are only two terms, it can also be called a bynomial.

e.mccormick · Answer

Or binomial.... i, not y.

anonymous · Answer

thanks

e.mccormick · Answer

So if you see either of those on the test, they would be right.  Mono- one, bi- two, tri- three.  All of those are -mial types for 1, 2, or 3 terms.  Quadratic and Cubic relate to the powers 2 and 3.

e.mccormick · Answer

Bi-cycle, Tri-cycle.  Same reasoning there.