It is known that there are three points a, B and C on the number axis, which are negative 24, negative 10 and 10. Two electronic ants a and B are facing each other from two points AC at the same time, and the velocity of a is 4 units Three questions first and third solution, online chat, urgent! Question 1: how many seconds later, the distance from a to ABC is 40 units. Why does the title say that a starts from a, but other netizens say that a is between ab

2 seconds, 5 seconds two solutions, in the calculation process, we can get 8 seconds is the root between AB, that is 0-3.5 seconds: 4x + (14-4x) + 34-4x = 40 get x = 2 in BC, that is 3.5-8.5 seconds: 4x + (x-3.5) X4 + 34-4x = 40 get x = 5 in BC, that is 3.5-8.5 seconds: 4x + (x-3.5) X4 + (x-8.5) X4 = 40 get x =
It is known that there are three points A.B.C on the number axis, which respectively represent the numbers - 24, - 10, and 10. Two electronic ants, a and B, respectively, are facing each other from two points A.C. the speed of a is 4 units per second, and that of B is 6 units per second
1、 Which point does a and B meet on the number axis?
2、 How many seconds later is the sum of the distance between a and ABC three points 40 units? If a turns back at this time, can b still meet on the number axis? If yes, find out the meeting point. If not, please explain the reason
One [10 - (- 24)] / (4 + 6) = 3.4 seconds
10-3.4×6=-10.4
Second, after s seconds, the condition holds
(1) after ∵ 400) seconds, the meeting condition is established
① When s = 2, a can meet at - 16, B at - 2, 14 + 4S = 6S, s = 7
② When s = 5, a is at - 4, B is at - 20, 6S + 16 = 4S, and there is no solution
The position of ABC on the number axis is known as shown in the figure
Figure 1
------c---------b---------0---------a--------------
Simplification: | a + C | - | B-C | + | 2b-a|
The above is a question
Figure 2
-------C -------- B -------- 0 -------- a -------- (the distance from the origin is about this position.)
Simplification: |b + c| - |a + c| - |b-a|
∵||||||||||||||||||||||||||||||||||||||||||||||
Given that the distance from a number on the number axis to the origin is root 7-root 3, find this number
The distance from the number to the origin (√ 7 - √ 3)
That is to say, | x-0 | = √ 7 - √ 3
The solution is x = ± (√ 7 - √ 3)
That is, x = √ 7 - √ 3 or x = √ 3 - √ 7
This number is the opposite of radical 7-radical 3
That is, root 7-root 3 or root 3-root 7
Root 7-root 3 or root 3-root 7
Attention can be positive or negative.
How can I get 20 by adding, subtracting, multiplying and dividing five nines and brackets?
(9＋9)÷9＋9＋9 =20
Tana = 2 / 3, then sin ^ 2a-2sinacosa + 1=
Sina / cosa = Tana = 2 / 3cosa = 3sina / 2 (Sina) ^ 2 + (COSA) ^ 2 = 1, so (Sina) ^ 2 = 4 / 13 (COSA) ^ 2 = 9 / 13sina / cosa > 0, so Sina * cosa > 0sinacosa = radical (Sina) ^ 2 * (COSA) ^ 2 = 6 / 13, so the original formula = 4 / 13-12 / 13 + 1 = 5 / 13
How to convert wind energy into electricity?
Wind power generation is that the wind drives the windmill to rotate. A magnet is installed on the windmill propeller, and then the magnetic induction line is cut to induce the power on
This way, this way, OK, done. Satisfied
Wind power ha, is the wind driven windmill rotation, windmill propeller above the installation of magnets, and then cut magnetic induction line, induction power
What is a △ 1 × a
2A
4_ 4_ 4_ 4=4,4_ 4_ 4_ 4=5,4_ 4_ 4_ 4=_ 6,4_ 4_ 4_ 4=7,4_ 4_ 4_ 4=8,4_ 4_ 4_ 4 = 9, using addition, subtraction, multiplication, division and brackets,
（4－4）×4＋4＝4
（4×4＋4）÷4＝5
（4＋4）÷4＋4＝6
4－4÷4＋4＝7
4－4＋4＋4＝8
4÷4＋4＋4＝9
Let Tana = 2, then 4sina-2cos / 5cosa + 3sina =; sin ^ 2A + 2sinacosa-3cos ^ 2A=
tana=sina/cosa=2
sina=2cosa
sin²a+cos²a=1
5cos²a=1
cos²a=1/5
4sina-2cos/5cosa+3sina
The numerator and denominator are divided by cosa
Original formula = (4tana-2) / (5 + 3tana)
=(8-2)/(5+6)
=6/11
sin^2a+2sinacosa-3cos^2a
=4cos²a+4cos²a-3cos²a
=5cos²a
=1
The numerator of cosa is divided by:
4sina-2cos/5cosa+3sina
=（4tana-2）/(5+3tana)
=6/11
sin^2a+2sinacosa-3cos^2a
=(sin^2a+2sinacosa-3cos^2a)/(sin²a+cos²a）
=（tan²a+2tana-3）/(tan²a+1)
=5/5
=1
4sina-2cos / 5cosa + 3sina
=(4tana-2)/(5+3tana)
=6/11
tana=2
sina=2cosa
sin²a+cos²a=1
therefore
cos²a=1/5
sin^2a+2sinacosa-3cos^2a
=4cos²a+4cos²a-3cos²a
=5cos²a
=5×（1/5）
=1
The first one is divided by cosa and the result is 6 / 11
Forget the formula

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