which if the following quartic functions has x = 1 and x =
![which if the following quartic functions has x 1 and x class=](https://us-static.z-dn.net/files/d96/77b9069fcf699636ca6890ac1d104992.jpg)
y = x⁴ +4x³ +4x² +4x +3
The coefficients of the offered quartics (in order) have 1, 1, 1, and 0 sign changes, respectively. Descartes' rule of signs tells you this means the first three choices all have one (1) positive real root, so the negative real roots -1 and -3 are not the only ones.
The only possible polynomial is the last one. Synthetic division of that polynomial by roots -1 and -3 leave the remaining factor as x²+1, which has only complex zeros.
The appropriate choice is ...
... y = x⁴ +4x³ +4x² +4x +3