If the data suggest a gradual increase or decrease, the line that best describes the data will be a
parabola, and the data can be summarized through quadratic regression. The least-squares curve
will be in the form y = ax^2 + bx + c.
When there is a sharp increase or decrease in values, an exponential regression may be the best way
to describe the data. The equation of the best-fit curve will be in the form y = abx.
There’s a lot of material in this chapter, but remember that it’s just the tip of the content pyramid.
You can use the Miscellaneous Topics Follow-Up Test to see how much you’ve picked up from this
chapter, but keep it in perspective. Whichever test you’re taking, it’s a higher priority to master the
material in the chapters preceding this one.
THINGS TO REMEMBER:
Rules of Imaginary NumbersComplex numbers
A number in the form a + bi, where a and b are real numbers, is called a complex number.Contrapositive
“If p, then q,” is logically equivalent to “If not q, then not p.”Percent Increase and Decrease