Given that P is a point in the plane of △ ABC, and PA + Pb + PC = 0, PA · Pb = Pb · PC = PC · PA = - 1, what is the area of △ ABC? There are vector symbols on the letters and zeros above ① From PA + Pb + PC = 0, we can prove that P is the center of gravity, but can we further find that △ ABC is an equilateral triangle? Why? ② From PA · Pb = Pb · PC = PC · PA = - 1, can we prove that P is perpendicular, and can we find that △ ABC is an equilateral triangle by combining with (1)? Also, the area is available on the Internet According to the meaning of the question, the triangle is an equilateral triangle, point P is the center of the triangle, and the distance from P to the three is √ 2. The solution is s = (3 √ 2) / 2 How to find it? How to get it? It seems that the title does not mention data. Is it found by PA · Pb = Pb · PC = PC · PA = - 1 and the triangle is an equilateral triangle? How to find it?

Given that P is a point in the plane of △ ABC, and PA + Pb + PC = 0, PA · Pb = Pb · PC = PC · PA = - 1, what is the area of △ ABC? There are vector symbols on the letters and zeros above ① From PA + Pb + PC = 0, we can prove that P is the center of gravity, but can we further find that △ ABC is an equilateral triangle? Why? ② From PA · Pb = Pb · PC = PC · PA = - 1, can we prove that P is perpendicular, and can we find that △ ABC is an equilateral triangle by combining with (1)? Also, the area is available on the Internet According to the meaning of the question, the triangle is an equilateral triangle, point P is the center of the triangle, and the distance from P to the three is √ 2. The solution is s = (3 √ 2) / 2 How to find it? How to get it? It seems that the title does not mention data. Is it found by PA · Pb = Pb · PC = PC · PA = - 1 and the triangle is an equilateral triangle? How to find it?

① : from & nbsp; PA + Pb + PC = 0 & nbsp; & nbsp;, we can get: P point is the center of gravity of triangle ABC. ②: from & nbsp; PA · Pb = Pb · PC = PC · PA & nbsp; = & gt; PA · Pb-Pb · PC = & nbsp; PA · pb-pc · PA & nbsp; = & gt; Pb (pa-pc) = PA (pb-pc) & nbsp; & nbsp; & nbsp; = & gt; Pb · CA = PA · CB & nbsp; & nbsp; & nbsp; As for the area: & nbsp; as shown in the figure, it is an equilateral triangle, and the area is divided into equal three parts. Let Pb = A and & lt; APB = & lt; APC = & lt; BPC = 120 degrees, then PA · Pb = a ^ 2cos 120 degrees & nbsp; = & gt; A = √ 2, so AB = radical 6 = & gt; & nbsp; s = 3 * radical 3 / 2 amount: I calculated: PA = Pb = PC = √ 2 ah! Anyway, the solution is like this! The solution is correct! I hope it can help you!
How many primes are there within 100?
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,
25 in total
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
25
25
There are: 2.357 11 13 17 19 23 29 31 37 41 43 53 59 61 67 71 73 79 83 89 97
The force of a fort is F. when an object with mass m leaves the fort, the velocity is v. then, when the mass is 2m, how much is v. the answer is v / 2
For the problem of force and speed, I usually do it from momentum angle, energy angle, force and kinematics angle (with the increase of your knowledge and the difficulty of the problem, this is a must to master, many problems are solved by the combination of these aspects). For this problem, I don't recommend the momentum and motion angle upstairs. For this type of problem, it can be solved simply, But it's very troublesome if it's more complicated. My method is to do it from the perspective of energy
Conservation of energy: 1 / 2mV * V = 1 / 2mvv results in V / root 2
Sorry, I don't know how to square. My method is the best way to solve this kind of problem. The energy of artillery firing is conserved, so the solution is very simple
I hope I can help you,
In fact, this is a kinematic problem. The force of the fort is f, and the acceleration displacement of the object when it leaves the fort must be the same. That is to say, it can be solved by 2As = (VT) ^ 2 - (V0) ^ 2, and the initial velocity is 0
First 2F / MS = (VT) ^ 2 VT = root (2f / MS) = v
Second f / MS = (VT1) ^ 2 VT = root (F / MS)
Compared with the first, we get the second V '= V / (root 2)
Conservation of energy
mv^2=2mV^2
V = V / root 2
The conditions are not clear....
Please give me more details...
It is known that all the vertices of a triangular pyramid s-abc are on the sphere of the sphere o, that △ ABC is an equilateral triangle with side length 1, that SC is the diameter of the sphere o, and that SC = 2, then the volume of the pyramid is ()
A. 26B. 36C. 23D. 22
∵ △ ABC is an equilateral triangle with side length of 1, the radius of circumcircle of ∵ ABC is 33, the distance between point O and surface ABC is d = r2-r2 = 63, SC is the diameter of ball o, the distance between point s and surface ABC is 2D = 263, the volume of pyramid is v = 13s ∵ ABC × 2D = 13 × 34 × 263 = 26, so a is selected
What are prime numbers in 100
Prime numbers within 100 are 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
Hope to help you.
In the formula for calculating angular velocity, what should be replaced by π?
If you want to calculate the specific value of angular velocity, is π 3.14?
In angular velocity, π stands for semicircle. If the value is specific, it will always be 3.14 This constant of
Four vertices of a sphere, B, P, D, on the base of a pyramid,
If the volume of a regular pyramid is 16 / 3, calculate the surface area of the sphere
Because it is a regular pyramid, ABCD is a square, and the projection of P on ABCD is spherical center o
So the side length of ABCD is √ 2R and the height is r
Volume v = (√ 2R) ^ 2 * r / 3 = 16 / 3
R=2
The surface area of the sphere is s = 4 Π R ^ 2 = 16 Π
If the four vertices a, B, C and D of the bottom surface of the regular pyramid p-abcd are on the same big circle of the sphere o, and the point P is on the same big circle of the sphere o, then the radius of the sphere is
Dividing a fraction by an integer (except 0) is equal to multiplying the fraction by the integer______ .
A fraction divided by an integer (except 0) is equal to the reciprocal of the fraction multiplied by the integer
Formula of angular velocity of uniform circular motion
ω. How to read it?
Omega, let's hear it
ω(ǒmīgǎ)
Φ(fài)
If the four vertices of p-abc are all on a sphere with a volume of 500 triangles and the area of the small circle where plane ABC is located is 16 triangles, then the height of p-abc is higher than that of p-abc
If the four vertices of a triangular pyramid p-abc are all on a sphere with a volume of 500 third pie, and the area of the small circle where plane ABC is located is 16 pie, then the maximum height of the triangular pyramid p-abc is?
A.7 B.7.5 C.8 D.9
Better have a little process
As shown in the figure, let the radius of the ball be r. from the formula of the volume of the ball, we can get 43 π R3 = 5003 π,  r = 5
Let the radius of the small circle be r, then π R2 = 16 π, ∧ r = 4
Obviously, when the height of the triangular pyramid is higher than the center O, the maximum value is obtained;
From oo1 = 52-42 = 3, so high po1 = Po + oo1 = 5 + 3 = 8
So C
When the line between the center of a small circle and the center of a sphere is the height of a triangular pyramid, the height can be 5 + 3 = 8
Choose C