Given that x2 + y2-4x-6y + 12 = 0, point P (x, y) is any point on the circle, find the maximum value of Y / X I understand the idea of this question,

Given that x2 + y2-4x-6y + 12 = 0, point P (x, y) is any point on the circle, find the maximum value of Y / X I understand the idea of this question,

∵ circle x ^ 2 + y ^ 2-4x-6y + 12 = 0
That is, (X-2) ^ 2 + (Y-3) ^ 2 = 1
The center of the circle (2,3), radius r = 1
∵ P (x, y) is any point on a circle
And ∵ Y / X is the slope k of Po (o is the origin)
∵PO：y=kx
When Po is tangent to a circle
That is, 1 = │ 2k-3 │ / √ (1 + K ^ 2)
∴k=（4±2√3）/3
It can be seen from the combination of number and shape
（y/x）min=（4-2√3）/3
（y/x）max=（4＋2√3）/3

Fifth grade mixed operation questions
I want the fifth grade score mixed operation test, 10 questions. I'm so anxious. I beg you, elder brothers and sisters, for the multiplication and division method, remember to ask for the answers. Well written, I only have 24 treasures. I'll give them all to you,

(Note: 3 / 1 = one third) (1) 3 / 1 divided by 6 / 5 multiplied by 9 / 10 (2) 15 / 8 divided by 9 / 2 divided by 5 / 3 (3) 3 / 10 divided by (33 / 10 divided by 2) (4) 13 / 8 divided by 7 + 7 / 1 * 13 / 6 (5) 7 / 3 divided by 9 * 15 / 14 (6) 10 / 7 * 6 / 1 divided by 12 / 7 (7) 56 / 9 divided by 7 / 3-9 / 2

If the radius of a sector is reduced by 2 times and the central angle of the circle is increased by 2 times, the area of the sector will be reduced______

It's tripled

Why does a particle on a wave with transverse harmonic motion have transverse vibration velocity?
Isn't a particle moving in a vertical harmonic motion
The transverse wave function along the rope is y = 0.10 cos (0.01 π X-2 π T) M. Try to find
The maximum transverse vibration velocity of a particle on the rope?
This is the original question

First, let's talk about the wave function. The meaning of the wave function y = 0.10cos (0.01 π X-2 π T) is that the ordinate of the point with X as the abscissa at time t is y. secondly, what is the velocity? Velocity is the derivative of displacement to time. Therefore, to find the lateral velocity, we need to find the derivative of y to t first (here, we need to find the partial derivative of y to t, and give any value of X, y to t)

Cut a piece of rectangular paper 120 cm long and 80 cm wide into a square of the same size. There is no paper left. How long is the longest side of the square?
At least how many can be cut?
I'm short of wealth recently. I hope you can forgive me and answer the questions as soon as possible. I'll report to you by Yongquan in the future

The greatest common divisor of 120 and 80 is 40, so the longest side of a square is 40 cm

The relationship between displacement and time of uniform speed linear motion in senior one physics is solved!
When an object starts to slide down a smooth slope (the object moves in a straight line with uniform acceleration) and divides the displacement before it reaches the bottom into three equal segments, what is the ratio of time for the object to pass through each segment?
I want to know what formula to use
I don't know T1, T1
Copy it down first and ask the teacher tomorrow

Suppose that the displacement of each segment is x, the acceleration is a, the time passing through the first n segments is TN, and the time passing through the N segments is TN
After paragraph - x = (1 / 2) AT1 ^ 2, T1 = T1 = (2x / a) ^ 1 / 2
After the first two paragraphs: 2x = (1 / 2) at2 ^ 2, T2 = (4x / a) ^ 1 / 2 = (radical 2) T1,
T2 = t2-t1 = [(radical 2) - 1] T1
After the first three paragraphs: 3x = (1 / * 2) at3 ^ 2, T3 = (6x / a) ^ 1 / 2 = (root 3) T1,
T3 = t3-t2 = [(radical 3) - (radical 2)] T1
T1: T2: T3... = 1: [(radical 2) - 1]: [(radical 3) - (radical 2)]

As shown in the figure, the radius of the bottom of the cone is 5, and the length of the generatrix is 20. The shortest distance for a spider to return to point a after crawling along the side of the cone is ()
A. 8B. 102C. 152D. 202

The circumference of the bottom surface of the cone is 2 π × 5 = 10 π. Let the degree of the center angle of the side expanded view be n.. N π × 20180 = 10 π, and the solution is n = 90. For the side expanded view of the cone, the shortest distance is 202 + 202 = 202, so D

2 】4.

1. X = 10Y + 8, x = 12y-2, x = 48, y = 4. The student has 48 people and rents 4 cars
2. (1) substitute t = 0C, v = 100, t = 10C, v = 103.5l into v = Pt + Q. 100 = OP + Q ①, 103.5 = 10p + Q ②. From ①, q = 100-0 ③ so q = 100, from ②, q = 103.5-10p ④. Substitute q = 100 into ②, P = 0.35
3. Let a be x, B be y.0.5x + 0.7 = 35, 1, x + 0.4 = 40, 2. Multiply 1 by 2 - 2 to get y = 30. Substitute y = 30 into 1, 0.5x = 14, x = 18
There are 200 football players and 150 basketball players
5. Suppose the total income is x and the expenditure is y yuan. (1 + 20%) x - (1-10%) is 12000 + 11400 (1), X-Y = 12000 (2)
.
I've been fighting very hard. Give me some points and vote

The circumference of a semicircle is 30.84cm, and the area of the semicircle is calculated

Let the radius of semicircle be r cm, then & nbsp; & nbsp; 2R + π r = 30.842r + 3.14r = 30.84 & nbsp; & nbsp; 5.14r = 30.84 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; r = 30.84 △ 5.14 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; r = 63.14 × 62 △ 2 = 3.14 × 18 = 56.52 (square cm) answer: the area of semicircle is 56.52 square cm

Volume formula of quadrangular prism
Correction
Quadrangular pyramid

It's 1 / 3 times the base area times the height
The volume of an n-prism is one third of that of an n-prism