In Algebra II, a polynomial function is one in which the coefficients are all real numbers, and the exponents on the variables are all whole numbers. A polynomial whose greatest power is 2 is called a quadratic polynomial; if the highest power is 3, then it’s called a cubic polynomial. A highest power of 4 earns the name quartic (not to be confused with quadratic), and a highest power of 5 is called quintic.

When solving polynomial functions and equations, don’t let these common mistakes trip you up:

  • Forgetting to change the signs in the factored form when identifying x-intercepts

  • Making errors when simplifying the terms in f(–x) applying Descartes’ rule of sign

  • Not changing the sign of the divisor when using synthetic division

  • Not distinguishing between curves that cross from those that just touch the x-axis at an intercept

  • Graphing the incorrect end-behavior on the right and left of the graphs