1. The solution of equation (x-1) &# 178; = 4 is? 2, and the solution of one variable quadratic equation 1 / 4x & # 178; - 1 = 0 is? 3?

1. The solution of equation (x-1) &# 178; = 4 is? 2, and the solution of one variable quadratic equation 1 / 4x & # 178; - 1 = 0 is? 3?

1. (x-1) = 2 or (x-1) = - 2, so x = 3 or x = - 1
2. 1 / 4x ^ 2 = 1 = > 1 = 4x ^ 2 = > 2x = 1 or 2x = - 1 = > x = 1 / 2 or x = - 1 / 2
3. (4-x) x = 0 = > 4-x = 0 or x = 0 = > x = 4 or x = 0
1. 3 or - 1
2. 2 or - 2
3. 4 or 0
Three
Current unit conversion 0.65 =? Ma =? UA
650mA = 650,000 uA
0.65a = 650ma = 650000 microampere
The operation of integral
The sum of the three internal angles of a triangle is 180 degrees. If the first angle of the triangle is three times the second angle, and the third angle is 15 degrees larger than the second angle, then how many degrees is the second angle? What are the other two angles?
Set the second angle X
So the first angle: 3x
The third angle X + 15
So x + 3x + X + 15 = 180, x = 33 degree
First angle = 99 degree
Second angle = 48 degrees
Let X be the second angle
3x+x+(x+15)=180
The solution is x = 33
The first angle is 99 degrees
The third angle is 48 degrees
Let the second angle be x degrees
x+3x+x+15=180
5x=165
x=33
The first one: 33 * 3 = 99 (degrees)
Third: 33 + 15 = 48 (degrees)
If O, G and H are the outer center, center of gravity and perpendicular center of △ ABC respectively, we have a conclusion: vector Oh = vector OA + vector
If ob + vector OC holds, then vector og = --- vector oh
Because G is the center of gravity of △ ABC, the vector GA + the vector GB + the vector GC = 0
Because vector og = vector Ag - vector Ao
Vector og = vector BG vector Bo
Vector og = vector CG - vector Co
So 3 * vector og = (vector Ag + vector BG + vector CG) - (vector Ao + vector Bo + vector CO)
=-(vector GA + vector GB + vector GC) - (vector Ao + vector Bo + vector CO)
=-0 - (vector Ao + vector Bo + vector CO)
=-(vector Ao + vector Bo + vector CO)
=Vector OA + vector ob + vector OC
=Vector oh
So vector og = (1 / 3) * vector oh
Can sound rub against materials and convert sound energy into heat?
I'm not good at physics
Theoretically, sound itself is a kind of vibration and has energy, which can be transformed into other forms for use
sure
What's the difference between Coulomb and ampere?
What are they used for?
Coulomb is the unit of electric quantity. It refers to the total electric quantity of an object. The symbol is C. It is named in memory of the physicist Coulomb
Ampere is the unit of electric current, that is, the amount of electricity per unit time passing through a cross section of an object. The symbol is A. It is named in memory of physicist ampere
among
1 Coulomb = 1 ampere * second
If a steady current of 1 ampere is carried in the conductor, the charge passing through the cross-sectional area of the conductor in 1 second is 1 Coulomb
Coulomb is the unit of electric quantity. It refers to the total electric quantity of an object.
Ampere is the unit of current, that is, the amount of electricity per unit time passing through a cross section of an object
Coulomb is the force between two charges, f = kqq / R ^ 2
Ampere refers to the force on the charged wire in the magnetic field, f = bil
1 Coulomb = 1 ampere per second. Coulomb is the unit of electricity, and the symbol is C. It was named in memory of the physicist Coulomb. If the conductor carries a steady current of 1 ampere, the amount of electricity passing through the cross-sectional area of the conductor in 1 second is 1 Coulomb.
Who has
Operation of integral
Exercise questions for
Keep one for me, thank you!
It's a set of exercises, not a topic
Test question 1 of integral operation
1、 Multiple choice questions
1. The following calculation is correct ()
A． B．
C． D．
2. Equal to ()
A． B．
C． D．
3. If, then a equals ()
A． B． C．0 D．
4. If known, the following calculation is correct ()
A． B．
C． D．
5. When the side length of a square increases by 2cm, its area increases by 24cm. The original side length of the square is ()
A．5cm B．6cm C．8cm D．10cm
2、 Fill in the blanks
1. The cost price of a TV set is yuan, and the sales price is 25% higher than the cost price. Due to the overstock of stock, it is sold at 70% of the sales price. Then, the actual price of each TV set is________ Yuan
2. The monomials in the following integers are_________ The polynomials are_________ .
, ,－2
3. In polynomials, the term with the highest degree is________ It is________ Second, its coefficient is_________ .
4. If the value of the algebraic expression is 6, then the value of the algebraic expression is 6_________ .
5. Please write a quintic monomial with negative coefficient and letters________ .
3、 Answer questions
6. Calculation:
（1） （2） （3） （4）
（5） （6）
（7）
7. First simplify, then evaluate
(1) Among them
(2) Among them
8. For the formula
(1) Can you work it out without a calculator?
(2) Do you know the number of digits it calculates? What is the number of digits?
9. Each liter of a certain liquid contains harmful bacteria, and one drop of a certain insecticide can kill such harmful cells. Now, how many drops of this insecticide should be used to kill the harmful bacteria in this two liter liquid? If 10 drops of this insecticide is a liter, do you know how many liters of insecticide should be used?
Reference answer:
1、 Multiple choice questions
1．D 2．B 3．A 4．C 5．A
2、 Fill in the blanks
1.2. - 2; 3., 3, 4. - 9, 5
3、 Answer questions
6．（1） （2） （3） （4） （5） （6） （7）288
7．（1） ,12 （2） ,7
8. (1) omit (2), one digit is 1
9. Drops, 0.2 liters
Integral operation test question 2
1、 Fill in the blanks
1． ；
2． ；
3．
4. The calculated value is__________
5． ；
6. If the edge length of a cube is cm, its volume is_________ Cubic centimeter
7. If, then
8. The product of n different non-zero positive integers is a. if each number is expanded to 5 times, then their product is a_________
9． ；
10. Known According to the law of the preceding formulas, we can guess: (where n is a natural number)
2、 Multiple choice questions
11. Fill in ()
A． B．
C． D．
12. The following formula is correct ()
A． B．
C． D．
13. The value of an algebraic expression is ()
A. 0 B.2 C. - 2 d. uncertain
14. There are () that can be calculated by using the square difference formula
① ② ③
A．1 B．2 C．3 D．0
15. For any positive integer n, according to the program calculation, the output answer is ()
Square answer
A． B． C． D．1
16. In Formula 1, 2, 3, 5, the equivalent is ()
A．①④ B．②③ C．①⑤ D．②④
3、 Calculation problem (or simplified evaluation)
17．
18．
19．
20．
21．
22．
23．
24. Among them
4、 Answer questions
25. The original rectangular green space is transformed as follows: the length is reduced by 2M and the width is increased by 2m. After the transformation, a square green space is obtained, which is twice the area of the original green space. The area of the square green space after the transformation is calculated
Reference answer:
1．
2．
3．
4． 5． ； 6． 7． 8． 9． 10．
11．C 12．D 13．C 14．B 15．D 16．C
17． 18． 19． 20．37 21． 22． 23．1 24． 25．
708×354+355×355
32×56-78
Given that point O is the outer center of triangle ABC, h is the perpendicular center and BD is the diameter of circumscribed circle, we prove that (1) vector ah = vector DC; (2) vector Oh = vector OA + ob + OC
1. Connecting AD and HC, ah ⊥ DC is obtained from ah ⊥ BC and DC ⊥ BC. Similarly, ad ⊥ HC, so ahcd is a parallelogram, so ah = DC
2. Vector ah = vector DC = 2 vector ob + vector BC = 2 vector OC + vector CB
2 vector ah = 2 (vector ob + vector OC), and vector ah = vector Ao + vector oh
Give me a picture
Give me a picture
When speaking, there is sound energy. What energy does sound energy turn into?
RT.
The internal energy of MS air has not increased
The mechanical energy of P-wave, which is actually the kinetic energy of air molecules, can be summed up in the internal energy of air
Of course, you hear the sound. That's when the longitudinal wave propagates. The air molecules hit your eardrum and vibrate So that part of the energy is transformed from the molecular kinetic energy of the air into the kinetic energy of the eardrum vibration
Part of the internal energy
The other part is converted into the mechanical energy of the longitudinal wave that transmits sound
1. The basic unit of electric charge is (). A. ampere second B. ampere C. Coulomb D. kilogram 2. As long as () exists, there must be a magnetic field around it
1. The basic unit of charge is (C. Coulomb)
2. As long as there is (current), there must be a magnetic field around it
The basic unit of charge is Coulomb
C. Coulomb