If the azimuth angles of space vector are α, β and R, what is the sum of the squares of the sinusoids of these three angles

If the azimuth angles of space vector are α, β and R, what is the sum of the squares of the sinusoids of these three angles

α. β and γ are the three directions of vector v. it can be seen from Fig. 2 that the x-axis component X of V is the module of V multiplied by cos (α). Similarly, it can be deduced that the y-axis component Y of V is the module of V multiplied by cos (β) and the z-axis component Z is the module of V multiplied by cos (γ), which can be summarized as follows: cos (α) = v.x / | V | cos (β) = v.y / | V | cos (γ) = v.z

How to find the sine value of the angle between two vectors?

First, the cosine value is obtained, and then the sine value is obtained by trigonometric formula
cos=a*b/|a|*|b|
Cos ^ 2 + sin ^ 2 = 1 the sine value must be nonnegative

1. The condition that makes the formula √ x-4 meaningful is_________ .
2. If x ＜ 2, the correct result of simplifying √ (X-2) & sup2; + | 3-x | is as follows:_________________ .
3. If the square of equation (m-2) x minus 2 + (3-m) X-2 ≈ 0 is a quadratic equation of one variable, then M=__________ .
4. If X1 and X2 are the two roots of the equation 2x & sup2; - 3x-6 ≈ 0, then x & sup2; 1 + X & sup3; 2 = 0_______ .
5. If x ≈ - 3 is one root of the equation x & sup2; + MX + 3 ≈ 0, then the other root is_______ .

1、x>4
2、5-2x
3. M is not equal to 2
4、33/4
5、-1

If a commodity is sold at a 10% discount for two consecutive times and the price of each commodity is a yuan after the price reduction, then the original price of each commodity is ()
A. 0.92aB. 1.12aC. a1.12D. a0.81

Suppose the original price of the commodity is x yuan, then the price after the first discount is (x × 0.9) yuan. When the second discount, the original price becomes (x × 0.9 × 0.9) yuan, that is, the price after the discount = (x × 0.9) × 0.9 = a, and the solution is: x = a0.81. Then the original price of the commodity is a0.81 yuan

Given that the domain of F (x) is (0,1), find the domain of F [ln (2x - (π / 4))]

According to the meaning of the title:
0

Practical problems and mathematical problems of quadratic equation of one variable should be explained in detail, and those that are wrong should not be answered
A watermelon operator bought a batch of small watermelons at the price of 2 yuan / kg and sold them at the price of 3 yuan / kg. In order to promote sales, the operator decided to sell them at a lower price. After investigation, it was found that the small watermelons could be sold 40 kg more per day for every 0.1 yuan / kg reduction in price. In addition, the daily fixed cost such as rent was 24 yuan. If the operator wanted to make a profit of 200 yuan per day, he would have to make a profit, How much should the price of small watermelon be reduced per kilogram

I guess it's like that
Let X be reduced
(3-x-2）（200+40*x/0.1）-24=200
I'm always wrong in solving the equation. You can solve it yourself
In addition, let me tell you the law (selling price purchase price) (sales volume) = total profit. Basically, this is how to find the same quantity (*^__ ^*(hee hee

If a commodity is sold at a reduced price according to the season, if it is reduced by 10% at the current price, it will still make a profit of 180 yuan. If it is reduced by 20%, it will lose 240 yuan. How much is the purchase price of this commodity?

Suppose the current price is x yuan, from the meaning of the question: (1-10%) x-180 = (1-20%) x + 240, & nbsp; & nbsp; & nbsp; & nbsp; 90% x-180 = 80% x + 240, & nbsp; 90% x-180-80% x = 80% x + 240-80% x, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 10% x-180 = 240, & nbsp; 10% X

The cubic power of 3.14 × 10 has several significant numbers

I don't know the meaning, three?

If / M-N / = N-M, and / M / = 4, / N / = 3, then (M + n) (M + n) =?
ps:/… /Represents the absolute value!

/m/=4 /n/=3
m=-+4 n=-+3
Because / M-N / = N-M
So M-N

What are the concrete labor and abstract labor in the production of goods?

Concrete labor refers to the labor with different production purposes, objects, tools, operation methods and production results. Concrete labor produces the use value of goods. Abstract labor refers to the general human labor without difference. Abstract labor produces the value of goods. Concrete labor and abstract labor are two interrelated and opposite aspects formed in the same labor process