1, let the domain of the function f(x) be d, and the interval I is included in d. If any two points on the interval x 1 and x2 are x 1f(x2), the function f(x) is said to be monotonically decreasing on the interval I, and the monotonically increasing and monotonically decreasing functions are collectively called monotonic functions.

2. Repeat the experiment for n times under the same conditions, and observe whether the event A appears. Let nA be the frequency of event A in n experiments, and fn (a) be the frequency of event A. ..

3, random number table method: random number table sampling "three steps": the first step, number the individuals in the population; Step 2, select the starting number; The third step is to obtain the probability of the number of samples.

4. The radian number of positive angle is positive, the radian number of negative angle is negative, the radian number of zero angle is zero, || =, L is the arc length when the angle is the central angle, and R is the radius.

5. Commonly used logical sentences include: proposition, necessary and sufficient condition, full-name quantifier and existential quantifier.