Summary of mathematics knowledge in the second semester of junior one tabloid

Chapter 5: the key point of this chapter: the solution of linear inequality of one variable, the difficulty of this chapter: understand the solution set of inequality and the determination of solution set of inequality system, and correctly use the basic properties of inequality. 3. The key point of this chapter: thoroughly understand the difference between the basic properties of inequality and equality. (1) the concept of inequality: use inequality ("≠", "..."

The key points or knowledge of concise points in history lesson 2

Lesson 2 the Tang Dynasty in its heyday
1、 Empress Wu Zetian
1. Emperor: in 690, the name of the state was changed to Zhou
2. Measures: (1) strike down the royal family and other aristocratic groups in Tang Dynasty, recruit talents in many ways, and promote Yao Chong and song Jing
(2) Personally organize the compilation of agricultural books, issue them to the whole country, and guide agricultural production
(3) We should encourage the construction of water conservancy projects and the cultivation of mulberry and silkworm
(4) The unemployed people in Guanzhong and other places are allowed to move to places with vast territory and few people
(5) Tax relief and corvee
(6) Land reclamation, grain production as an important basis for inspection of local officials
3. Influence: social economy and culture continue to develop
2、 Kaiyuan heyday: the founder -- Li Longji, Emperor Xuanzong of Tang Dynasty
1. Measures: (1) appointment of talents, personal assessment of county magistrate
(2) Develop production, encourage wasteland reclamation, build water conservancy, arrange finance, clear land and household registration
(3) Abolish the harsh law of torture in the period of Wu Zetian
(4) Advocate thrift
2. Results: the economy and culture of Tang Dynasty had a new development and entered the heyday

PEP seventh grade history Volume 2 unit 1 knowledge points

The solution equation is 27.8-9x = 12

Transference
27.8-12.5=9x
15.3=9x
9x=15.3
x=15.3÷9
x=1.7

I would like to ask all the graphics area formula!

Rectangle: S = ab {rectangle area = length × width}
Square: S = a ^ 2 {square area = side length × side length}
Parallelogram: S = ab {area of parallelogram = bottom × height}
Triangle: S = ab △ 2 {triangle area = bottom × height △ 2}
Trapezoid: S = (a + b) × h △ 2 {trapezoid area = (upper bottom + lower bottom) × height △ 2}
Circle (circle): S = Πr ^ 2 {circle (circle) area = circumference × radius × radius}
Circle (positive circle outer ring): S = Πr ^ 2 - Πr ^ 2 {circle (outer ring) area = circumference × outer ring radius × outer ring radius - circumference × inner ring radius × inner ring radius}
Circle (circle sector): S = Πr ^ 2 × n / 360 {circle (sector) area = circumference × radius × radius × sector angle / 360}
Surface area of cuboid: S = 2 (AB + AC + BC) {surface area of cuboid = (L × W + L × H + W × h) × 2}
Surface area of cube: S = 6A ^ 2 {surface area of cube = edge length × edge length × 6}
Surface area of sphere (positive sphere): S = 4 Π R ^ 2 {surface area of sphere (positive sphere) = circumference × radius × radius × 4}
Ellipse s = π (circumference) × a × B (where a and B are the length of the major and minor axes of the ellipse respectively)

As shown in the figure, it is known that CD is the height of AB side in △ ABC, and ⊙ o with CD as the diameter intersects Ca and CB at points e, F and g respectively, which are the midpoint of AD. proof: Ge is the tangent of ⊙ o

It is proved that: (1) connecting OE, De, ∵ CD is the diameter of ⊙ o, ∵ AED = ∠ CED = 90 °, ∵ G is the midpoint of AD, ∵ eg = 12ad = DG, ∵ OE = OD, ∵ 3 = 4, ∵ 1 + ∠ 3 = 2 + 4,

Summary of mathematics knowledge in the second semester of junior one tabloid