What is a quartic function with only two real zeros, x = 5 and x = 9?

Question

jdoe0001 · Answer

hmmm  a quartic, meaning 4 degree
so, 4 answers or solutions, or zeros
so... say
x = 5
x = 5
x = 9
x = 9

so   there, meaning $\begin{array}{llll}
x=5\implies &x-5=0\
x=5\implies &x-5=0\
x=9\implies &x-9=0\
x=9\implies &x-9=0\
\end{array}
\ \quad \
(x-5)(x-5)(x-9)(x-9)=\textit{original polynomial}$

phantomcrow · Answer

A quadratic means it has a degree of 2 as in $$ax^2+bx+c$$ and since x= 5 and x=9 are it's solutions, then the factored polynomial is $$(x-5)(x-9)$$ and the expanded form is $$x^2-14x+45$$