1. Let the set of points (x, y) satisfying y ≥ x-a be a, and the set of points (x, y) satisfying y ≤ - x + B be B, where a and B are positive numbers and a is not equal to an empty set (1) What is the relationship between a and B? (2) Find the area of the figure represented by a and B 2. If the gun fires the bullet at the initial velocity V vertically and ignores the air resistance, then when the distance between the bullet and the muzzle is what, the kinetic energy of the bullet is the general of its standing potential energy? (expressed in letters) 3. An object slides down from the height h of the inclined plane and stops after sliding on the horizontal plane for a certain distance. The measured horizontal distance between the stop and the starting point is L. if there is no kinetic energy loss when the object slides to the bottom of the inclined plane, the dynamic friction coefficient between the inclined plane and the horizontal plane and the object is u, and u is calculated Don't give me one answer

1. Let the set of points (x, y) satisfying y ≥ x-a be a, and the set of points (x, y) satisfying y ≤ - x + B be B, where a and B are positive numbers and a is not equal to an empty set (1) What is the relationship between a and B? (2) Find the area of the figure represented by a and B 2. If the gun fires the bullet at the initial velocity V vertically and ignores the air resistance, then when the distance between the bullet and the muzzle is what, the kinetic energy of the bullet is the general of its standing potential energy? (expressed in letters) 3. An object slides down from the height h of the inclined plane and stops after sliding on the horizontal plane for a certain distance. The measured horizontal distance between the stop and the starting point is L. if there is no kinetic energy loss when the object slides to the bottom of the inclined plane, the dynamic friction coefficient between the inclined plane and the horizontal plane and the object is u, and u is calculated Don't give me one answer

(1) - B ≤ a ≤ B (2) (b ^ 2-A ^ 2) / 2No. 2: let the bullet meet the condition when it reaches h, then the potential energy of the bullet is MGH, and the kinetic energy is half of the potential energy, that is MGH / 2
2X+3X+4X=18
2X+3X+4X=18
(2+3+4)x=18
9x=18
X=2
2. Answer: 9x = 18
X=2
1 X5 = 5 2x4 = 8 3x? = 13 4x5 = 20 5x1 = 5 what is the question mark?
Nine
　　13÷3=13/3
13/3
thirteen-thirds
What's the number of times 3 equals 13
The known set a = {x | 2 ≤ x ﹤ 7}, B = {x | 3 ﹤ x ﹤ 10}, C = {x | x ﹤ a}, (I) (CRA) ∩ B
(II) if a ∩ C ≠ empty set, find the value range of real number a
（1）
A={x|2≤x＜7}
CRA = {x | X & lt; 2 or X ≥ 7}
therefore
（CRA）∩B={x|7≤x<10}
（2）
If a ∩ C ≠ an empty set, then
A must be on the right side of 2
So a & gt; 2
It is known that the solution of {2x-y = - 3, 4x + 5Y = 1} is ()
x= -1
Y=1
In the triangle ABC, a = 2, a = π / 4, if the triangle has two solutions, then the value range of B
Are the changes of kinetic energy, potential energy and mechanical energy related to work
First, B must be greater than 2, otherwise there can only be one solution
Secondly, if there are two solutions, then the distance from point B to edge AB cannot be greater than or equal to 2. If it is equal to 2, there is only one solution. If it is greater than 2, there is no solution at all
Therefore, B cannot be greater than 2 / sin45 = 2 * 2 ^ 2 (that is, 2 × radical 2)
So the value range of B is greater than 2 and less than 2 × root 2
The change of kinetic energy, potential energy and mechanical energy must be related to work, because the measure of energy conversion is work
How much energy is transformed is how much work is done
The energy of external work is reduced and the energy of external work is increased
In a word: work is a measure of energy change. So about
This problem is actually very simple. First of all, we can find the range of angle B (0 ° - 135 °), and then according to the sine theorem, you can easily see the answer
Did you?
Physics I know = Mathematics I'm really poor
There are two ways to change energy, one is to do work, the other is to transfer heat
Yeah, I don't know
2＜b＜2√2
Mathematics answers 6x = 3x-12 2y-1 / 2 = 1 / 2y-3 4-3x = 4x-3 3x-2 = 2x + 1 2x-8 = 3x 6x-7 = 4x-5
6X=3X-12
2Y-1/2=1/2Y-3
4-3X=4X-3
3X-2=2X+1
2X-8=3X
6X-7=4X-5
6X=3X-12
2Y-1/2=1/2Y-3
4-3X=4X-3
3X-2=2X+1
2X-8=3X
6X-7=4X-5
If you think it's good, you can add it to 150
6X=3X-126X-3X=-123X=-12X=-42Y-1/2=1/2Y-32Y-1/2Y=-3+1/21.5Y=-2.5Y=-5/34-3X=4X-3-3X-4X=-3-4-7X=-7X=13X-2=2X+13X-2X=1+2X=32X-8=3X2X-3X=8-X=8X=-86X-7=4X-56X-4X=-5+72X=2X=1
How to solve 3x-4x5 = 16
3x-4x5=16
3x=16＋20
3x=36
x=12
Given the set a = {x | X-2 > 0}, B = {x | x-a > 0}, if AUB = B, try to find the intersection of (CRA) and (CRB)
AUB=B
The intersection of (CRA) and (CRB)
=Cr(AUB)=CrB={x|x-a
Solving equations 2x + 3Y + 4 4x-5y = - 3
2x+3y=4 1
4x-5y=-3 2
Formula 1 * 2 4x + 6y = 8 3
Formula 3-2 gives 11y = 11
Y=1
x=(4-3)/2=1/2
x=1/3
Y=1
x=1/2 y=1