High scoring questions urgent! How to calculate the TEMPO of a song

Now on the official explanation of DJ skills. In this part, we will explain from the perspective of what a DJ thinks about when mixing, so that we can understand the method of DJ mixing more clearly.

Step 1 Count the beats: At the beginning of the practice of beating, first take a not too difficult and paradoxical electronic dance music record as the first track and put it on one of the two record players, assuming that the left one is good, press the start button of the record player to make the record player start to rotate, and carefully place the stylus on the record as shown in the picture. At the time of **, silently count the loop of the left track in your mind 22345678 32345678 42345678....

12345678...And keep circulating. Remember:

If you can't even hear this loop, you can't become a DJ. The recognition of cycles can be trained by silently counting 1234 in the mind when listening to **. After all, every DJ comes through slowly like this.

A1(1): Copy.

The situation in which 3 people in the first class of the first grade were not elected as members of the committee by BAI was du: 0 out of 3 people in the first class and 15 out of the other 42 people.

The DAO probability is p0=c[3,0]* c[42,15] c[45,15]=, so the probability that someone in a class of 3 people will be elected as a committee member (at least 1 person will be elected as a committee member) is 1-p0=

A1(2):

15 classes elect 15 members, and someone from each class is elected as a member, which happens to be one (member) per class.

One member is elected from the three representatives of each class, and there are c[3,1]=3 election methods, so there are 3 15 election methods, and the probability is 3 15 c[45,15]=4 per 100,000).

Note: C[45,15] is the number of combinations of 15 out of 45, which is equivalent to excel's combin(45,15, other similar).

A2: Using the polynomial probability formula, there is a direct joint probability distributed is.

p(x,y,5-x-y)=5!/[x!y!(5-x-y)!where x,y=0,1,2,3,4,5, and x+y<=5).

where x is the number of levels 1, y is the number of levels 2, and (5-x-y) is the number of levels 3.

They are the basic probabilities of the level.

30 is also a high score? Who to fool? Compared to the questions you asked and your rank, it is really pitiful, obviously lacking sincerity, asking people to help you.

Hero, add a few more points and then talk about it first.

Here's the answer:

My conclusion is that it can be vertical.

First, find the derivation of f(x).

f'(x)=3x^2-2(a+b)x+ab

At x=s and x=t, the pole plants are the two roots of the quadratic function when the derivative is equal to 0, and bring in s,t

This yields s+t=2(a+b) 3=(4 3) 3,..1)

s*t=ab/3 ..2)

a（s,s(s-a)(s-b))

b(t,t(t-a)(t-b))

oa point multiplied by ob=st+s(s-a)(s-b)*t(t-a)(t-b).

st+st[(s-a)(t-a)]*s-b)(t-b)]

st+st[st-a(s+t)+a^2][st-b(s+t)+b^2]

Substituting (1) and (2) into the above equation yields:

oa point multiplied by ob = st+st[ab 3-2a(a+b) 3+a 2]*[ab 3-2b(a+b) 3+b 2].

st+st[(a^2-ab)/3]*[b^2-ab)/3]

st+st*ab*(a-b)(b-a)/9

st[1-ab*(b-a)^2/9]

b-a)^2=(a+b)^2-4ab

12-4ab

After substitution, you get:

OA point multiplied by ob=st[1-ab*(12-4ab) 9].

To OA and OB vertically, since ST is not equal to 0, then there is:

1-ab*(12-4ab)/9=0

9-ab*(12-4ab）=0

Simplification yields:

4(ab)^2-12ab+9=0

2ab-3) 2=0, so: ab=3 2, at this time by calculation when.

A= 3- 6 2, B = 3 + 6 2, OA and OB are vertical.

^1.(1) In 2010, the automobile plant produced 10,000 vehicles.

2) The average growth rate required in the next 5 years (2 (1+10%) 5) (1 5)-1=

2.(1) Standard deviation of income = 4500

Income for: A: Regression coefficient of expenditure = 1

Correlation coefficient between income and expenditure =

2) Calculate the regression equation for fitting expenditure to income:

The coefficient of regression of expenditure to income is b =

a= —1040

So, the regression equation for fitting expenditure to income is: y (a c in the bottom right corner) = —1040+

3) For every 1 yuan increase in income, the average increase in expenditure is 1 yuan.

3.(1) The average number of workers in the first quarter (1800+1850+1850+1870+1870+1872) was 6,1852.

The average number of employees in the first quarter = (2300 + 2350 + 2350 + 2370 + 2370 + 2372) 6 = 2352.

The proportion of workers in the number of employees in the first quarter of the enterprise was 1852 2352*100%.

2) The labor productivity of workers in the first quarter was 10,000 yuan.

There are too many topics, can you give a representative one, draw inferences.

(1) Let the plan be x, then (100%+10%)x=1080, so x=982 The GDP of the previous year is x

The percentage increase is 1080 909-1=

2) The average mass is found to mean u, and the variance d 2 confidence level is found as:

p([x-u]/d

1. The planned GDP of the reporting year = 1080 (1+10%), the GDP of the previous year = (1080 (1+10%)) (1+8%), the reported annual GDP increased over the previous year = 1080 ((1080 (1+10%)) (1+8%))1=

2. Confidence level p([x-u] d

Question 1: Find the mean x first, specifically according to the weighted average, each group is weighted by the median, specifically: 97 in the first group, 99 in the second group, 101 in the third group, 103 in the fourth group, 105 in the fourth group, and then (97 2 99 3 101 34 103 7 105 4) 50

Reuse the mean to find the standard deviation

n=50 = do the math for yourself f(z)=95% can push out f=

Standard deviation n under the root number

The limit error δ=z·

The confidence interval is (mean x - δ, mean x + δ).

The second question is to extrapolate according to the limit error.

Q3 Steps of hypothesis testing.

The first step is to propose a null hypothesis and an alternative hypothesis (where 1is a two-sided hypothesis test; 2.is a hypothesis test on the right; 3.

is a hypothesis test on the left. Because hypothesis testing is the rejection of the null hypothesis in the probabilistic sense, the null hypothesis must contain an equal sign. Which test to use depends on the specific problem, especially when choosing the right or left test).

secondly, the test statistic is constructed and its value is calculated.

3) thirdly, given the level of significance, determine the critical value (delineate the rejection domain and the acceptance domain);

4) Fourth, compare the value of the test statistic with the critical value and make a statistical decision to accept or reject the null hypothesis.

Question 2 Seasonal index = monthly average Total monthly average multiplied by 100%.

Question 3··· The data is so confusing...

Leave a QQ 214359312 talk about it in detail when the time comes.

Alas, think for yourself. Neither will I.

Excel.

Column A: The first few singles.

The entries of the self-grid input selection are baia, b, c, d, and the result of the subsequent cell format input.

du, column b to find the total number of options.

zhi=countif(a:a,a:a)-1,c column to find the total number of choices =counta(a:a)-4, ca column to find more weight than dao = b1 c1, pull down.

Insert - Chart - Standard Type - Pie Chart.

Excel.

The first few cells of column A enter the items selected A, B, C, D, and the result of the subsequent unit format is entered, column B finds the total number of options back = countif(a:a,a:a)-1, column c finds the total number of choices answer=counta(a:

a)-4, Ca column to find the specific gravity = B1 C1, pull down.

Insert - Chart - Standard Type - Pie Chart.

Calculate how many people choose this option and see which option has the most people. It can be made as () or () or it can be represented by a person who writes 1 or takes a graphic, and then counts it.

Figure 3 (2) After correcting the above errors, when trying to touch the switch, it is found that the ammeter has an indicator, the voltmeter has no indication, and the bulb does not light up. Upon inspection, the voltmeter is intact and properly connected, and the bulb is also intact, then the cause of this failure may be:

2 (6 minutes) If two lamps marked with the words "6v 3w" and "9v 6w" are connected in series at both ends of a power supply, only one lamp emits normal light and the other lamp emits dim light, then which lamp emits normally and what is the voltage of the power supply?

Figure 8S1 shows the number of the ammeter and voltmeter when both S2 are disconnected.

2) When both S1 and S2 are turned on, the electrical power consumed by the whole circuit.

The resistance of a motor coil is 1, and the voltage applied at both ends of the coil is 2 V, and the current is, and the motor is positive.

Regular work. When finding the electric energy consumed by the motor for 1 min of normal operation, there are two differences.

Solution. Xiao Ming's solution: w=uit=2v

Xiaohua solution: w=i2rt=( 1 60s=

1.Which student do you think is doing the right thing, please make a judgment and explain why.

5 points) Find out what is the electric heat generated by the motor working normally for 1min?

1. With the improvement of people's living standards, refrigerators have entered thousands of households. However, many families are afraid to store more food in the refrigerator for fear of the cost of electricity. Is it true that the more food stored in the refrigerator, the more electricity it consumes? The students in the physics group ** this question.

First of all, they made it clear that in order to study this problem, they only needed to change and measure the amount of electricity consumed by the refrigerator in a certain period of time, and then compare it.

How do you measure electrical energy? After repeated discussions, they found a simple way to use the energy meter at home to measure the electricity consumed by the refrigerator in two days by taking advantage of the time when the family was out on weekends.

Here's how they do it:

Xiao Ming, Xiao Hua, and Xiao Liang respectively filled the refrigerator at home with food, half of the food, and a quarter of the food, and measured the power consumption of the refrigerator in the corresponding time. h、?h、?

h。From this, they came to the conclusion that "the more food the refrigerator stores, the more electricity it consumes".

Please point out what is wrong with them in the process:

A rice cooker that works at the rated voltage, the power is 440W, and the current is 2A, what is the rated voltage of this rice cooker?

2.In the circuit shown in Figure 16, the bulb L is marked with the words "6V 3W", the maximum resistance of the sliding rheostat R1 12, close S1 first, slide the sliding rheostat P to the left end, and the bulb L emits light normally at this time Q:

1) What is the power supply voltage? What is the resistance of the bulb when it emits light normally?

3r1+3 rc = 2r3+2r1

2r3 = r1+3 rc………The voltage at both ends of the power supply is constant, and in circuits A and B, according to U=IRI1(R3+RB)=I2(R3+R1).

3rb = 2r3+5r1………The maximum power consumption of the circuit should be that switches S1 and S2 are closed, and only R3 is connected. The minimum power consumption should be R3, R1, and the sliding rheostat RB are all connected in series to the circuit.

The total voltage of the circuit is certain.

2r3 = r1+rb ……According to the formula, it can be obtained: r3 2rc

In the C circuit, the current is constant, p = 2pc = 2 10w = 20w

The diagram shows the circuit diagram of the experiment for "measuring the power of a small bulb". The middle figure shows the electrical components required for the experiment. Among them, the power supply is two new dry batteries, the rated voltage of the bulb is, and the filament resistance is about 10.

1) Replace the wire with a pen line, and connect the components into an experimental circuit according to the circuit diagram;

2) After connecting the circuit, a student found that the bulb was not lit and the ammeter did not read when the switch was closed, but the voltmeter did. Try to analyze the fault of the circuit;

3) Another student connected the circuit according to the circuit diagram, and found that the light bulb was particularly bright when he closed the switch, what does this mean?

4) In order to determine the rated power of the bulb, should it be adjusted**? How many volts do you make a voltmeter read? If the ammeter reads as shown in the image, what is the rated power of that bulb?

Analysis] 1) The power supply is two new dry batteries, and the rated voltage of the bulb is, therefore, the range of the voltmeter should be 3V; If the filament resistance is about 10, the current in the circuit is estimated to be i=ur=about about that, not exceeding, and the ammeter range should be selected; Also pay attention to the connection of the positive and negative binding posts of each meter, and the sliding rheostat should play a role in changing the resistance, that is, one for the two binding posts of A and B, and one for the two binding posts of C and D.

2) After closing the switch, the bulb does not light up and the ammeter does not read, but the voltmeter does. This shows that except for the branch of the bulb between B and C, the other parts are open, but the current is too small, so the ammeter reading is zero. Circuit faults generally have short circuits and open circuits, here is not a short circuit, because when short circuit, the ammeter should have an indicator, and the voltage between B and C measured by the voltmeter should be zero; The fault here is the broken branch of the bulb between B and C.

3) When the switch is closed, the bulb is particularly bright, indicating that the current in the circuit is too large and the resistance is too small, because the sliding blade of the sliding rheostat is not placed at the maximum resistance.

4) To measure the rated power, the sliding rheostat must be adjusted so that the two ends of the bulb are rated voltages, and the current representation in the reading figure is calculated according to the P and U and I.

3) The sliding vane of the sliding rheostat is not placed at the maximum resistance.

4) The sliding rheostat should be adjusted, and the reading of the voltmeter is, and the rated power of the bulb is p = u i =.

Comments] The experiment of "measuring the power of a small bulb" is basically the same as the experiment of "voltammetry resistance measurement", and the knowledge tested is:

1) Circuit connection, that is, the pen line is used instead of the wire to connect the experimental circuit. (2) The use of sliding rheostats: the main thing is that the binding post connected to the circuit should be "up and down" and whether the sliding blade is in the maximum position.

3) The use of ammeter and voltmeter, that is, how to connect to the measured circuit, the connection method of positive and negative binding posts, and the selection of range. As long as we pay attention to these problems, we will not find it difficult to solve them.