The curve represented by polar coordinate equation P (1 + sin ^ 2 θ / 2) = 1 is

The curve represented by polar coordinate equation P (1 + sin ^ 2 θ / 2) = 1 is

ρ(1+sin²(θ/2))=1
ρ(3-cosθ)/2=1
3 √ (X & sup2; + Y & sup2;) - x = 2 (√ denotes root)
8x²-4x+9y²-4=0
(16/9)(x-1/4)²+2y²=1
It represents an ellipse with the center at (1 / 4,0), the length of its major axis at 3 / 2 and the length of its minor axis at √ 2
The polar coordinate equation sin @ = 1 / 2 (P belongs to R, P is greater than or equal to 0) indicates that the curve is ()
A. Two intersecting lines
B. Two rays
C. A straight line
D. A ray
sina=1/2
A = π / 6 or 5 π / 6
It's two rays
B
The curve represented by polar coordinate equation ρ sin Λ 2 θ - 2xos θ = 0 is?
If both sides of the original equation are multiplied by ρ, we can get:
ρ²sin²θ- 2ρcosθ=0
Then: Y & # 178; - 2x = 0
That is: Y & # 178; = 2x
The equation represents a parabola with vertex at origin and focal coordinate (1 / 2,0)
The curve represented by polar coordinates 4 ρ sin2 θ / 2 = 5-2 ρ cos θ is
4sin²(θ/2)=
4ρsin^2(θ/2)=5-2ρcosθ
4ρ(1-cosθ)/2=5-2ρcosθ
2ρ(1-cosθ)=5-2ρcosθ
2ρ-2ρcosθ=5-2ρcosθ
2ρ=5
ρ=5/2
x^2+y^2=5/2
Represents a circle with (0,0) as the center and radius of 10 / 2 of the root
How many watts of power is the starting motor of model 125 motorcycle?
The battery is 12 volts, the capacity is less than 10 ampere hours, the most is more than 100 watts! The working time can only be a few seconds, the time is long, it will burn and fire!
If 4 empty mineral water bottles can be replaced by 1 bottle of mineral water, now there are 15 empty bottles, how many bottles of mineral water can you drink at most?
My method is: 15 bottles can be replaced by 3 bottles of water, after drinking with the remaining 3 empty bottles, a total of 6 empty bottles
Then take four out of the six bottles and change another one
I can drink four bottles of water altogether
But the answer is five bottles
I know how to do it on the 7th floor, but there are only three bottles left at the last time, which can't be changed
You can think about it. Since four empty mineral water bottles can be replaced by one bottle of mineral water, there is only one empty bottle left after drinking. That is to say, three empty bottles are just one bottle of water (only there are no bottles after drinking)
So 15 bottles can drink 15 / 3 = 5 bottles of water, just can divide
Well, five bottles can be changed, four bottles can't be changed
Of the 15, you can get three bottles of water, three bottles and six bottles after drinking
There are three bottles left after another drink
Taking three bottles for one is not enough for four, but after drinking that and adding the original three, it's just four bottles
So it's five bottles
Three bottles of water can be replaced for 15 bottles, and then the remaining three empty bottles are added after drinking. There are six empty bottles in total.
Then take four of the six bottles and you can change another one.
Now there are three empty bottles
Borrow an empty bottle for another and return it immediately
5 bottles in total
15 can be changed into 3 mineral water, and there are 3 empty bottles left
After drinking three mineral water, you can change another one, and there are three left
Three plus one is five bottles
I came across a practical problem: the sum of Xiaoming's and his father's ages is 34 years old now, and his father will be 24 years older than Xiaoming three years later. The problem tells us a condition that "my father will be 24 years older than Xiaoming three years later", which is the key to solve the problem.
The answer is always wrong. In either case, it's four bottles
12 empty bottles can be exchanged for 3 bottles of mineral water,
We got three more empty bottles. Now there are six empty bottles
Exchange four empty bottles for one and get another one
Now there are three empty bottles
Return the flat immediately after changing a bottle
You can have a bottle
5 bottles in total
It took Xiaohong 10 days and Xiaoli 8 days to read the same book. What's the speed ratio between Xiaohong and Xiaoli?
4/5
How much electricity does a 100 watt bulb consume per hour
nothing
Ten hours of power consumption!
Calculation method:
1000 divided by the wattage of the bulb
The circuit shown in the figure shows that the current through the milliammeter is about______ Ma, the current through the ammeter is about______ Ampere
Through the analysis of the circuit diagram, it can be seen that two 500 Ω resistors in series are connected in parallel with 2 Ω resistor, so the current passing through two 500 Ω resistors can be ignored. In this way, the circuit is simplified to 1000 Ω and 2 Ω resistors in series and then connected in parallel with 200 Ω resistor. The ammeter measures the current in 2 Ω and 1000 Ω series branch. When calculating the current, it can be approximately considered that I = ur = 20v1000 Ω = 0.02A = 20mA; the current passing through 200 Ω is I = ur = 20v1000 Ω = 0.02A = 20mA '= ur' = 20v200 Ω = 0.1A = 100mA, so the reading of the milliammeter is 20mA + 100mA = 120mA, so the answer is: 120; 0.02
Calculate a room type space, the effective inner diameter size is 50 cm long and 44 cm wide, to put item a, item a is also square, the overall size is 18 cm long and 9 cm wide, calculate how many can be put.
Is the simple division of volume feasible?
You can put up to 91
There are many kinds of placement schemes. Of course, the number of items a can be placed in each scheme is not exactly the same. All the situations should be taken into account and then calculated and compared. Now only the best scheme is taken as an example to illustrate the thinking method, and other schemes should be calculated by yourself
The thinking process is as follows:
Step 1: all objects are placed at the height of 18cm and the bottom of 16cm * 9cm, so that the number of layers can be placed is 127 / 18 = 7.06, and the whole is 7 layers. (the reason why this scheme is the best is that the remaining space on the roof is the smallest, which is 50cm * 44cm * 0.6cm = 1320cm ^ 3. If other schemes are placed at the height of 16, the remaining space on the roof is 127 / 16 = 7.94, which is also 7 layers, But the space waste is 50cm * 44cm * 0.94cm = 2068cm ^ 3)
Step 2: with 16 * 9 as the bottom, there are two situations: one is that the edge with side length of 9 is placed in the direction with space length of 50cm; the other is that the edge with side length of 9 is placed in the direction with space length of 44cm
Step 3: in case 1, the number of layers that can be placed is (50 / 9) rounding * (44 / 16) rounding = 5 * 2 = 10. At this time, 10 * 7 layers can be placed = 70. But it is not finished, because there is 44-16 * 2 = 12cm remaining space along the direction of the edge with length of 44 (because 12 > 9). The plane dimension of remaining space is 12 * 50, and the edge with length of 9 can be placed along the direction of the remaining 12, Multiply by the number of layers, 3 * 7 = 21. So this scheme can place 70 + 21 = 91
Step 4: in case 2, the number of layers that can be placed is (50 / 16) rounding * (44 / 9) rounding = 3 * 4 = 12, and at this time, 12 * 7 layers = 84 can be placed. There is 50-16 * 3 = 2cm remaining space along the direction of the side with length of 50, and 44-9 * 4 = 8cm remaining space along the direction of the side with length of 44. The plane size of the remaining space is 2 * 8, no matter how to place it, Can not put a object. So in this case, only 84 can be placed
Other schemes are similar in thinking method. After comprehensive comparison, we can get the conclusion that 91 a objects can be placed at most
Several friends directly divide the volume of space by the volume of a, the method of rounding is not comprehensive
Can you put down 107 pictures at most
enen
You can't just divide,
If you put it on the right side, 50 / 18 can only put 2, 44 / 9 can only put 4, 127 / 16 can only put 7, so you can put 2x4x7 = 56,
It is calculated separately in vertical position and inverted position.
The final number is the number that can be placed on the length multiplied by the number that can be placed on the width multiplied by the number that can be placed on the height, so of course, we have to choose how to place more than one pendulum. We can't do this or that for a while
127 / 9 max = 14,50 / 18 = 2,44 / 16 = 2; 50... Expanded
You can't just divide,
If you put it on the right side, 50 / 18 can only put 2, 44 / 9 can only put 4, 127 / 16 can only put 7, so you can put 2x4x7 = 56,
It is calculated separately in vertical position and inverted position.
The final number is the number that can be placed on the length multiplied by the number that can be placed on the width multiplied by the number that can be placed on the height, so of course, we have to choose how to place more than one pendulum. We can't do this or that for a while
127 / 9 maximum = 14, 50 / 18 = 2, 44 / 16 = 2; 50 / 16 = 3, 44 / 18 = 2, so choose the second one, and finally put up the 14x3x2 = 84
In my opinion, it should use large space volume: 50 * 44 * 127 = 34925m & # 179; remove small square volume: 18 * 9 * 16 = 324m & # 179; the result is about 107.79, the number is rounded to 107
84
No, different shapes are not allowed.
How many should be put as long as possible: 50 / 18 = 2... 14
How many are the widest: 44 / 9 = 4... 8
The highest number: 127 / 16 = 7... 15
The best: put two
Maximum width: 4
Top: 7
Then you can put 2 * 4 * 7 = 56
Look at the rest of the space: 14cm long, 8cm wide, 15cm high. No matter how you put the rest of the space, you can't put it in.. ... unfold
No, different shapes are not allowed.
How many should be put as long as possible: 50 / 18 = 2... 14
How many are the widest: 44 / 9 = 4... 8
The highest number: 127 / 16 = 7... 15
The best: put two
Maximum width: 4
Top: 7
Then you can put 2 * 4 * 7 = 56
Look at the rest of the space: 14cm long, 8cm wide, 15cm high. No matter how you put the rest of the space, you can't put it in..
If the width is the height, 14 * 2 * 2 = 56 can be obtained
Length as height: 5 * 2 * 7 = 70
So 70 at most.
Actually, I don't know if LZ is right. I'm a little suspicious myself, but I believe the idea is right. There's something wrong with the details