Will the stars fall from the sky
When I was a child, looking at the stars in the night sky, I always had a lot of beautiful reverie and questions. For example, why can't the sun, moon and stars fall down in the sky? Isn't it hard for Americans to live on the earth upside down at our feet? And so on
RELATED INFORMATIONS
- 1. The actual area of the stadium is calculated by drawing a figure with a scale of 1:2000. The length of the stadium is 3.5cm and the width is 1.5cm
- 2. As shown in the figure, a pentagram is an axisymmetric figure, and it has______ There is an axis of symmetry
- 3. The corresponding curves () A. There is only one common point B. There are two common points C. There is no common point D. the number of common points is determined by the parameter t
- 4. Please use vector to represent the inner center of triangle, the center of gravity, the center of gravity, the center of gravity, and their characteristics and conclusions (do not define them)
- 5. It is known that 0 < α < π / 4, β is the minimum positive period of F (x) = cos (2x + π / 8), and vector a = (Tan (α + 1 / 4 β) Given that 0 〈α 〈π / 4, β is the minimum positive period of F (x) = cos (2x + π / 8), vector a = Tan (α + 1 / 4 β), - 1), B = (COS α, 2), and a · B = m, find the value of 2cos α Λ 2 + sin2 (α + β) / cos α - sin α
- 6. The range of y = 2cos ^ 2x + 5sinx-4 Please give the process
- 7. Find the range of the following function: 2cos ^ 2x + 5sinx-1 under the root sign
- 8. The maximum value of the function y = 5sinx + cos2x is______ .
- 9. The range of function y = 2cosx square + 5sinx-4,
- 10. The range of function y = - 2cos (x + π / 3) + 3
- 11. As shown in the figure, it is known that ∠ AOE is a flat angle, OD bisects ∠ Coe, OB bisects ∠ AOC, ∠ cod: ∠ BOC = 2:3, find the size of ∠ cod, ∠ BOC
- 12. As shown in the figure, all quadrangles are squares and all triangles are right triangles. The side length of the largest square is a. then the sum of the areas of the four small squares a, B, C and D in the figure is a______ .
- 13. Find the probability that the chess piece happens to be at vertex B? There is a chess piece at vertex a of positive tetrahedron ABCD. It is equally possible for it to move from one vertex to the other three vertices. Now we roll the dice and decide whether the chess piece will move according to the number of dice. If the number of dice is 1 or 2, the chess piece will not move. If the number of dice is 3 or 4, the chess piece will move once. If the number of dice is 5 or 6, the chess piece will move twice. Now we roll the chess piece twice, what is the probability that the chess piece will just be at vertex B?
- 14. As shown in the picture______ There are three triangles______ A parallelogram with______ It's a trapezoid
- 15. Given that the function f (x) = x2 + BX + 1 is an even function on R, then the real number B=______ The solution set of inequality f (x-1) < x | is______ .
- 16. Let the distribution function f (x) = a + bartanx of random variable x, and find P {x}
- 17. On the inequality system of X: 2x + 53 > x − 5x + 32 < x + A has five integer solutions, then the value range of a is______ .
- 18. Given 14 (XX + YY + zz) = (x + 2Y + 3Z) ^ 2, find X: Y: Z
- 19. How to calculate 125 times 72
- 20. The calculation formula of variance I'm going to dictate it, inside [variance formula s ^ 2 = 1 / n [(x1-m) ^ 2 + (x2-m) ^ 2 +... + (xn-m) ^ 2] I don't understand this. I only remember the x1-x pull-out or something