Urgently need all the mathematical theorems and laws of junior high school!!! Fast

The answer is already known... This is my previous method. I don't know if it applies to you.

In general, it is divided into many stages, for example, the first and second, the first and the second. The first time, the first time + the second time. 1st time + 2nd time + 3rd time.

When you do it, mark it vertically with 123456Write the numbers that can be analyzed horizontally, so that it should be easier to find the law directly, just practice more, and the high school entrance examination will not be too difficult.

Over the years... Alas, the math scores are not as good as day by day, people are gradually depressed, looking for and seeking, miserable and miserable, and they are not good at finding rules, why do they lose to girls every time? Looking at Li Yilong, Zheng Wanjing's eyes were empty, alas... The two of them are a natural pair.

According to your idea, I have to press the phone for at least half an hour, don't do it, lose.

1, is squared.

2. The numerator, the denominator plus a few, is represented by n.

3. Look for patterns obliquely.

1. The velocity formula of uniform linear motion:

Find velocity: v=s t

Find the distance: s=vt

2. The speed formula of variable speed linear motion: v=s t

3. The relationship between the weight and mass of an object: g=mg

g = 4, the definition of density.

Find the density of a substance: =m v

Find the mass of the substance: m = v

Find the volume of the substance: v=m

4. Calculation of pressure.

Definition: p=f s (the substance can be applied in any state) liquid pressure: p= gh (h is the depth).

Find the pressure: f=ps

Find the force area: s=f p

5. Calculation of buoyancy.

Weighing method: f float = g—f

Formula method: f float = g row = v row g

Floatation method: F float = g object (v row v object).

Suspension method: F float = g matter (V row = V matter).

6. Leverage balance condition: f1l1=f2l2

7. Definition of work: w=fs

8. Power definition: p=w t

For the case of uniform linear motion: p=fv

f is power) 9, mechanical efficiency: =w useful w total.

For lifting objects:

w useful = gh (h is the height).

W total = FS10, bevel formula: FL = gh

11. Endothermic and exothermic conditions when the temperature of the object changes.

Q aspiration = cmδt

t=t-t0）

Q amp = cmδt

t=t0-t）

12. Calculation of the heat emitted by fuel combustion: q discharge = qm

13. Thermal equilibrium equation: q suction = q discharge.

14. Heat engine efficiency: =w useful

q put. q-amp=qm).

15. Current definition: i=q t

q is the amount of electricity, and the unit is coulombs.

16. Ohm's law: i = u r

Deformation voltage: U=IR

Deformation resistance: r=u i

17. The characteristics of the series circuit: (taking the series connection of two pure resistive electrical appliances as an example) the lead-quiet relationship of the voltage: U=U1+U2

Relationship of current: i=i1=i2

Relation of resistance: r=r1+r2

18. The characteristics of the parallel circuit: (taking the parallel connection of two pure resistive Huai slag appliances as an example) the relationship between voltage: u=u1=u2

Relationship of current: i=i1=i2

The relationship of resistance: 1 r = 1 r1 + 1 r2

19. Calculation of electric work: w=uit

20. The definition of electric power: p=w t

Common formula: p=ui

21. Joule's law: q amp = i2rt

For purely resistive circuits: q amp = i2rt

u2t/r=uit=pt=uq=w

22. Calculation of the total power of the leakage circuit of the lighting electric section: p=p1+p1+......

Solution: There is a problem to know that the LED, the sliding rheostat and the power supply are in series relationship, so there is V(LED)+V(Sliding Rheostat)=V(Power) is known V(LED)=3V, V(Power)=, V(Sliding Rheostat)=

Since the current = 20mA, the total resistance of the circuit can be calculated in units, and the resistance of the LED is twice that of the sliding rheostat according to V(LED)=3V(sliding rheostat)=.

Since the total resistance is 225, the resistance of the LED is 150, and the resistance of the sliding rheostat is 75

Solution: r=u i=3v

r total = r lamp + r resistance = u total i =

r-resistance = 750

This answer is correct, and the identification is complete.

LED worked normally when it was 3V.

Solution: a b c 50 6a 8b 10c 0 a 6a 9 b 8b 16 c 10c 25 0 a 3 b 4 c 5 0a 3 0, a 3b 4 0, b 4c 5 0, c 5 3 4 5

i.e.: a b c

This triangle is a right-angled triangle with c as the hypotenuse.

A 2 + B 2 + C 2 + 50 = 6A + 8B + 10C that is, (A 2-6A + 9) + (B 2-8B + 16) + (C 2-10C + 25) = 0

i.e. (a-3) 2+(b-4) 2+(c-5) 2=0 a=3, b=4, c=5

a^2+b^2=9+16=25=c^2

ABC is a right triangle.

a²＋b²＋c²＋50－6a－8b－10c＝0﹙a²－6a＋9﹚＋﹙b²－8b＋16﹚＋﹙c²－10c＋25﹚＝0﹙a－3﹚²＋b－4﹚²＋c－5﹚²＝0a－3＝0, a＝3

b－4＝0, b＝4

c－5＝0, c＝5

a²＋b²＝c²

Therefore, δabc is a right triangle.

1: No, the mass of Qiling of 2L of high trembling Qi is much greater than the mass of 1L of hydrogen and 1L of oxygen.

2: Celery 2H2+O2=2H2O

According to the equation, it can be seen that 8 grams of oxygen can only react completely with 1 gram of hydrogen, so an excess of 1 gram of hydrogen can only produce 9 grams of water, and 1 gram of hydrogen is left. Thank you.

1. Not true. First of all, I don't know the state of the water, whether it is a liquid or a gas, so their density is not the same. Even if the generated water is water vapor, 1 l of water should be generated.

2. Not true. 2h2+o2——2h2o

1mol 1mol Since there is less oxygen, it is done according to oxygen to produce water. i.e. 9 grams.

2h2+o2=(ignition)2h2o; No, oxygen will not react completely, and the remainder will be in proportion to the rubber-coarse reaction formula; The second is that hydrogen will not complete the whole reaction, and the remaining 1 gram of hydrogen will be according to the mass fraction.

When n is an odd square, let m = n, then the nth point coordinate is (m,0), the n-1 is (m,1), and the n-2 is (m,2). The law is consistent until the n-m number, 2012=45 -13, and the coordinates of the 2012th point are (45,13).

Similarly, when n is an even number squared, let m = n, then the nth point coordinate is (1,m-1), the n+1 is (1,m), and the n+2 is (2,m).

(2012 Tai'an) As shown in the figure, in the plane Cartesian coordinate system, there are several points with integer abscissa respectively, and their order is arranged in the direction of " " in the figure, such as (1,0),(2,0),(2,1),(1,1),(1,2),(2,2)....According to this law, the abscissa of the 2012th point is 4545 solution: according to the figure, the total number of points is equal to the square of the abscissa of the point in the lower right corner of the x-axis, for example: the abscissa of the point in the lower right corner is 1, there are 1, 1=12, when the abscissa of the point in the lower right corner is 2, there are 4, 4=22, when the abscissa of the point in the lower right corner is 3, there are 9, 9=32, and when the abscissa of the point in the lower right corner is 4, there are 16, 16=42，...When the abscissa of the point in the lower right corner is n, there are n2, 452=2025, 45 is an odd number, the 2025th point is (45,0), and the 2012th point is (45,13), so the abscissa of the 2012th point is 45

The abscissa of the 2012th point is 45