1, trigonometric function:

Trigonometric function is an important concept in mathematics, involving concepts such as angle and radian. In junior high school, we will learn more about the concept and application of trigonometric function, but we can also start to understand it in grade five.

Common trigonometric functions are sine function, cosine function and tangent function. Sine function represents the ratio of the opposite side to the hypotenuse of an angle, which is recorded as sin θ; Cosine function represents the ratio of the adjacent side to the hypotenuse of an angle, which is recorded as cos θ; The tangent function represents the ratio of the opposite side to the adjacent side of an angle, and is recorded as tanθ.

2. Average value:

The average value refers to the sum of all values of a set of data divided by the number of this set of data. In the fifth grade, we have learned how to calculate a simple average, but to expand our knowledge is to learn how to calculate a weighted average.

Weighted average means that different data have different weights, and the average value is calculated by weighting. For example, we can use different weights to calculate the average score of a student in several subjects.

3. Probability formula:

In the fifth grade mathematics, we have learned the basic concept of probability and the calculation method of probability. But extended knowledge includes more probability formulas. For example, the conditional probability formula is used to calculate the probability of one event under the premise of another event; Multiplication principle is used to calculate the probability of multiple events occurring simultaneously.

4, logarithmic function:

Logarithmic function refers to an exponent whose number is based on a positive number. In junior high school, we will learn more about the concept and application of logarithmic function, but we can also start to understand it in the fifth grade.

Common logarithmic functions are natural logarithmic function ln(x) and common logarithmic function log 10(x). Logarithmic functions have some important properties, for example, logarithmic functions can be transformed into each other, and multiplication can be transformed into addition.

5, cube root formula:

In the fifth grade, we have learned simple cubic operation and solving cubic roots. But expanding knowledge includes using cube root formula to solve more complex problems.

Cubic root formula refers to the formula for solving a certain number of cubic roots, including three solutions. Cubic root formula can be applied to physics, engineering and other fields, such as calculating the volume and mass of a cube.