The weather team measured the temperature at 2:00, 8:00, 14:00 and 20:00 on the day as 13 degrees, 16 degrees, 25 degrees and 18 degrees respectively. Calculate the average temperature of the day

The weather team measured the temperature at 2:00, 8:00, 14:00 and 20:00 on the day as 13 degrees, 16 degrees, 25 degrees and 18 degrees respectively. Calculate the average temperature of the day

(13+16+15+18)/4=15.5

The temperature records of the red scarf meteorological group one day are 6:12, 8:15, 10:18, 12:23, 14:25, 16:20, 18:17 and 20:14. Q: when is the average temperature of this day (6:00-20:00)?

10:00

How can the square of sin α be transformed into sin α

Square it directly. According to the angle range, take positive and negative
For example:
sin²α=k （k≥0）
sinα=±√k

There are 14 pieces of RMB 5 yuan and 10 yuan, 100 yuan in total. How many pieces of RMB 5 yuan and 10 yuan each

In fact, this problem can be done in a simple way
If it's all 10 yuan, it's 140 yuan
This produces a difference of 40 yuan, which is caused by 5 yuan
So 40 / 5 = 8
That is, there are 8 sheets for 5 yuan and 6 sheets for 10 yuan. There is no need to set up equations at all
Please choose as the best answer, thank you!

64,48,40,36 fill in the blanks ()

The next number should be 34
Rule: the difference between the first digit and the second digit is 16, 8 and 4, which are all powers of 2, so the next one should be 2
So the next number is 34

Sum and prime numbers within 100

Prime number:
2,3,5,7
11,13,17,19
23,29
,31,37
,41,43,47
,53,59
,61,67
,71,73,79
,83,89
,97
Sum: all except one

Derivative of y = - sin (x / 2) * [1-2 (COS (x / 4) ^ 2]

=-sin(x/2)*（-cos（x/2））
=0.5sinx
∴y‘=0.5cosx

Would you please write the formula? As shown in the figure, the area of the overlapping part of the two rectangles is equivalent to 8 / 1 of the area of the large rectangle and 6 / 1 of the area of the small rectangle. What is the ratio of the area of the large rectangle and the area of the small rectangle?

If you regard 1 / 8 of a large rectangle and 1 / 6 of a small rectangle as 1, then the area of a large rectangle is 1 divided by 1 / 8 = 8, then the area of a small rectangle is 1 divided by 1 / 6 = 6, and the ratio of a large rectangle to a small rectangle is 8:6 = 4:3
1 divided by 1 / 8 = 8
1 divided by 1 / 6 = 6
The ratio of large rectangle to small rectangle is 8:6 = 4:3

"Any two adjacent natural numbers are coprime numbers", right

This conclusion is undoubtedly correct when 0 is not a natural number. Now 0 is also a natural number. We only need to study whether the two adjacent natural numbers "0 and 1" are prime numbers or not. According to the definition of Coprime number in volume 10 of mathematics of six-year primary school in nine-year compulsory education: "there are only two numbers with common divisor 1

Judgment question: integers that are not natural numbers, if not zero, must be negative integers
This sentence is right or wrong
I don't understand = = need detailed analysis
I think it's right, but the answer is wrong

That's right. Natural numbers are positive integers, excluding 0
If the integer is not a natural number, then it is a zero or a negative integer
Since it's not zero, it's a negative integer
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I found it. It was stipulated by the state in 1994
Natural numbers include zero
In that case, it's wrong
So my answer is wrong