A number in the complex plane. It can be written as \(a + bi\), where \(a\) and \(b\) are real numbers and \(i^2 = \text-1\).

 

The degree of a polynomial in \(x\) is the highest exponent occuring on \(x\) when you write the polynomial out as a sum of non-zero constants times powers of \(x\) (with like terms collected).

The number \(e\) is an irrational number with an infinite decimal expansion that starts \(2.71828182845\ .\ .\ .\), which is used in finance and science as the base for an exponential function.

How the outputs of a function change as we look at input values further and further from 0.

A function \(f\) that satisfies the condition \(f(x) = f(\text-x)\) for all inputs \(x\). You can tell an even function from its graph: Its graph is symmetric about the \(y\)-axis.

An experimental study collects data by directly influencing something to determine how another thing is changed.

A function is a rule that takes inputs from one set and assigns them to outputs from another set. Each input is assigned exactly one output.

A sequence in which each term is a constant times the previous term.

The time it takes for a material to decay to half of its original value. For example, the half-life of Carbon-14 is about 5,730 years. This means that if an object started with 10 micrograms of Carbon-14, then after 5,730 years it will have 5 micrograms of Carbon-14 left.

The line \(y =c\) is a horizontal asymptote of a function if the outputs of the function get closer and closer to \(c\) as the inputs get larger and larger in either the positive or negative direction. This means the graph gets closer and closer to the line as you move to the right or left along the \(x\)-axis.

An equation which is true for all values of the variables in it.

A number on the imaginary number line. It can be written as \(bi\), where \(b\) is a real number and \(i^2 = \text-1\).

An irrational number is a number that is not rational. This means it cannot be expressed as a positive fraction, a negative fraction, or zero. It cannot be written in the form \(\frac{a}{b}\), where \(a\) and \(b\) are integers and \(b \neq 0\).

For example, the numbers \(\pi\) and \(\text{-}\sqrt{2}\) are irrational numbers.

The logarithm to base 10 of a number \(x\), written \(\log_{10}(x)\), is the exponent you raise 10 to get \(x\), so it is the number \(y\) that makes the equation \(10^y = x\) true. Logarithms to other bases are defined the same way with 10 replaced by the base, e.g. \(\log_2(x)\) is the number \(y\) that makes the equation \(2^y = x\) true. The logarithm to the base \(e\) is called the natural logarithm, and is written \(\ln(x)\).

A logarithmic function is a constant multiple of a logarithm to some base, so it is a function given by \(f(x) = k \log_{a}(x)\) where \(k\) is any number and \(a\) is a positive number (10, 2, or \(e\) in this course). The graph of a typical logarithmic function is shown. Although the function grows very slowly, the graph does not have a horizontal asymptote.

The maximum expected difference between an estimate for a population characteristic and the actual value of the population characteristic. 

The value halfway between the maximum and minimum values of a period function. Also the horizontal line whose \(y\)-coordinate is that value.

The power to which a factor occurs in the factored form of a polynomial. For example, in the polynomial \((x-1)^2(x+3)\), the factor \(x-1\) has multiplicity 2 and the factor \(x+3\) has multiplicity 1.

The natural logarithm of \(x\), written \(\ln(x)\), is the log to the base \(e\) of \(x\). So it is the number \(y\) that makes the equation \(e^y = x\) true.

A specific distribution in statistics whose graph is symmetric and bell-shaped, has an area of 1 between the \(x\)-axis and the graph, and has the \(x\)-axis as a horizontal asymptote. 

An observational study collects data without influencing the subjects directly.

A function \(f\) that satisfies \(f(x) = \text-f(\text-x)\) for all inputs \(x\). You can tell an odd function from its graph: Its graph is taken to itself when you reflect it across both the \(x\)- and \(y\)-axes. This can also be seen as a 180\(^\circ\) rotation about the origin.

The length of an interval at which a periodic function repeats. A function \(f\) has a period, \(p\), if \(f(x+p) = f(x)\) for all inputs \(x\).

A function whose values repeat at regular intervals. If \(f\) is a periodic function then there is a number \(p\), called the period, so that \(f(x + p) = f(x)\) for all inputs \(x\).

A polynomial function of \(x\)  is a function given by a sum of terms, each of which is a constant times a whole-number power of \(x\). The word “polynomial” is used to refer both to the function and to the expression defining it.

The identity \(\sin^2(x) + \cos^2(x) = 1\) relating the sine and cosine of a number. It is called the Pythagorean identity because it follows from the Pythagorean theorem.

A selection process in which each item in a set has an equal probability of being selected.

A randomization distribution is a distribution created to analyze the results of an experiment. The data from the control and treatment groups are randomly redistributed into two groups, and the statistic of interest is calculated for each group. The distribution of the statistics of interest from each redistribution is the randomization distribution.

A rational function is a function defined by a fraction with polynomials in the numerator and denominator. Rational functions include polynomials because a polynomial can be written as a fraction with denominator 1.

A rational number is a number that can be written as a positive fraction, a negative fraction, or zero. It can be written in the form \(\frac{a}{b}\), where \(a\) and \(b\) are integers and \(b \neq 0\). 

• 0.7 is a rational number because it can be written as \(\frac{7}{10}\).
• The numbers 0, 3, \(\text{-}\frac{3}{4}\), and 6.7 are all rational numbers. 

A number on the real number line.

Histogram from 16.5 to 25.5 by 0 point 5’s. Handspan, centimeters. Beginning at 16.5 up to but not including 17, height of bar at each interval is .001, .007, .013, .016, .052, .059, .087, .132, .159, .132, .104, .098, .069, .032, .023, .010, .004, .002, 0.

A histogram where the height of each bar is the fraction of the entire data set that falls into the corresponding interval (that is, it is the relative frequency with which the data values fall into that interval).

A point on the graph of a function that is higher than any of the points around it.

A point on the graph of a function that is lower than any of the points around it.

A sample is a subset of a population. For example, a population could be all the students at one school in grade 11. One sample of that population is all the grade 11 students who are taking Spanish.

A sampling distribution is a distribution of statistics obtained from samples drawn from a specific population. For example, a group of students draw several samples from a population that has 70% of items that Pass. The proportion of papers from each sample that are marked Pass is shown in this dot plot.

A list of numbers, possibly going on forever, such as all the odd positive integers arranged in order: 1, 3, 5, 7, . . . .

A survey is a set of questions given to people to seek their responses.

One of the numbers in a sequence.

In an experiment where you are comparing two groups, one of which is being given a treatment and the other of which is the control group without any treatment, the treatment is the value of the variable that is changed for the treatment group.

The circle in the coordinate plane with radius 1 and center the origin.

The vertex form of a quadratic expression is \(a(x-h)^2 + k\), where \(a\), \(h\), and \(k\) are constants and \(a \neq 0\). The vertex of the graph is at the point \((h,k)\).

The line \(x=a\) is a vertical asymptote for a function \(f\) if \(f\) is undefined at \(x=a\) and its outputs get larger and larger in the negative or positive direction when \(x\) gets closer and closer to \(a\) on each side of the line. This means the graph goes off in the vertical direction on either side of the line.