![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
Find the range of function f (x) = x & # 178; / X & # 178; + 1
0 to 1
What is the range of the function y = 5 / x2-2x + 2?
y=5/(x²-2x+2)=5/[(x-1)²+1]
∴0＜y≤5
The range of function y = 1-2x / x2
Using the separation parameters
The closest to 1.5 kg are: A, a bicycle B, a bottle of coke C, a watch D, and a pencil
1.5L coke is the closest to 1.5kg, because the density of coke and water is about the same, 1kg / L
Xiao Ming's father is a taxi driver. After hearing that his father drove back, xiao ming helped his father sort out the fare, and found that people with 5 yuan, 10 yuan and 20 yuan
There are 44 pieces of RMB, totaling 500 yuan, of which 10 yuan is equal to 20 yuan. According to this information, can you calculate the number of each of the three kinds of RMB
Let 10 yuan have X sheets, 20 yuan have X sheets, and 5 yuan have (44-2x) sheets
10x+20x+5×（44-2x）=500
30+220-10x=500
20x+220=500-220
20x=280
x=14
44-2x = 44-14 × 2 = 16 (yuan)
5 yuan: 16 × 5 = 80 yuan
20 yuan: 14 × 20 = 280 yuan
10 yuan: 14 × 10 = 140
As shown in the figure, Xiao Hong cuts a 4 cm wide strip from a square, and then cuts a 5 cm wide strip from the remaining rectangular paper along the direction parallel to the short side. If the area of the strips cut twice is exactly the same, what is the area of each strip? What is the area of the original square?
Suppose the side length of the square is xcm, then according to the meaning of the question: 4x = 5 (x-4), the solution is: x = 20. Then 4x = 80 (cm2), 20 × 20 = 400 (cm2). Answer: the area of each strip is 80cm2, the area of the original square is 400cm2
In △ ABC, the opposite sides of angles a, B, and C are a, B, and C, respectively. Tanc = 37. (I) find the value of COSC; (II) if CB · CA = 52, and a + B = 9, find the length of C
(I) ∵ Tanc = 37, ∵ sinccosc = 37. And ∵ sin2c + cos2c = 1, the solution is COSC = ± 18. ∵ Tanc > 0, ∵ C is an acute angle. ∵ COSC = 18. (II) ∵ CB · CA = 52, ∵ abcosc = 52. The solution is AB = 20. And ∵ a + B = 9, ∵ A2 + B2 = 41. ∵ C2 = A2 + b2-2abcosc = 36. ∵ C = 6
Classic of famous teachers
Dow's Theory -- Robert Leia's stock market barometer -- Hamilton's great speculator series (5 books) -- Andre costolaney's securities psychology of great speculators -- Andre costolaney's technical analysis of stock market trend -- Robert D. Edward John McGee's futures market technology
The perimeter of a square surrounded by a wire is 47.1 decimeters. If the wire is used to form a circle, how many square meters is the area of the circle?
The circumference is 47.1 decimeters
So the radius is 47.1 △ 3.14 △ 2 = 7.5 decimeters
So area = 3.14 × 7.5 × 7.5 = 176.625 square centimeter
First simplify and then evaluate: ab-2b + 4a-4-a ^ 2 of A-2, where a = - 6, B = - 4 of 3
(4a-4-a^2)/(ab-2b+a-2)
= (-a^2-(a-2)^2)/(a-2)(b+1)
=(-36-64)/(-8)(-1/3)
=-300/8
= -37.5
RELATED INFORMATIONS
- 1. Find the range of function y = x2-2x + 2, X ∈ (0,3]
- 2. Let y = f (x). When x changes from x0 to x0 + △ x, the change of function value △ y is equal to () A. f（x0+△x）B. f（x0）+△xC. f（x0）•△xD. f（x0+△x）-f（x0）
- 3. How to distinguish nonlinear function from linear function?
- 4. Mathematical quadratic function It is known that the parabola y = ax ^ 2 + BX + C intersects the x-axis at two points a and B (point B is on the right side of point a, and ab = 8), and intersects the y-axis at point C, where point a is on the negative half axis of x-axis, point C is on the positive half axis of y-axis, and the length (OA) of line segments OA and OC
- 5. Judge whether the function group is linear correlation sin 2t,cos t,sin t Are these three functions linearly related? How to prove them? If there are K1, K2, K3 which are not all zero such that K1 * sin 2T + K2 * cos t + K3 * sin t = 0 is constant on interval I, it is said that they are linearly correlated on interval I
- 6. How to judge whether the ordinary differential equation is linear or not? As the title ~ the best example! Why is m * [y (x)] '+ T * siny = 0 nonlinear? Our teacher said that because there is a function of Y, it is nonlinear
- 7. 57. Find the differential of the following functions: (1)y=3x^2 (3)y=lnx^2 (5)y=e^(-x)*cosx (7)y=ln√(1-x^3) (9）y=tan(x/2)
- 8. Differentiation (function) Find d ^ 2Y / DX ^ 2 of each function 1.y=cosx/(√x) 2.x^3-3xy+y^3=4 3.sin y +cos x=1 4.x^2/3+y^2/3=a^2/3 1.1/4x^-5/2[(3-4x^2)cosx +4xsinx] 2.10xy(x-y^2)^-3 3.(cos^2ycos x+sin^2xsin y)/cos^3y 4.(a^2/3)/(3x^4/3 y^1/3)
- 9. The relationship between derivative and differential, derivative can calculate tangent and slope, so what does differential calculate? indicating contrast
- 10. A sufficient condition for differentiability in binary functions, right
- 11. The method of finding the range of fractional function For the form y = ax ^ 2 + BX + C / ex ^ 2 + FX + G and the function domain is not r (such as x > 0), the general method is to find the range ----------- Note that the general solution, that is to say, the fractional function can not be directly converted to the mean inequality, nor can it be directly separated from the constant form Here, the domain of definition of X is not r, so the discriminant method should not be used Big brother, the discriminant method to define the domain must be r The question is how to ask Answer 3L: the definition field is not R. for example, how to find the value field of x = 2 to the power of T?
- 12. When using discriminant method to find the range of function, how to judge whether the quadratic coefficient of discriminant is equal to 0?
- 13. Finding the total differential of the function u = x2 + sin (Y / 3) + e ^ XY
- 14. Finding the total differential Du of the function u = ln (2x + 3Y + 4Z ^ 2)
- 15. Let u = XY (x > 0, X ≠ 1), then Du=
- 16. Given DZ = 5xdx + Y & # 710; 2dy, find δ & # 710; 2Z / δ y δ x, (second order mixed partial derivative), and δ is the sign of partial derivative
- 17. Let z = Z (x, y) be the implicit function determined by the equation x ^ 2 + Z ^ 2 = ysin (Z / x), and find the partial derivative of Z to x, y I am a math idiot
- 18. In Chapter 3, for any piecewise function, if the left and right derivatives exist at the piecewise point, can we say that the function is continuous at the tapping point? Both left and right numbers exist, but they are not necessarily equal
- 19. For dy / DX... No formula Finding dy / DX y-e^(-xy)=x-e^(xy) Challenge yourself!
- 20. Dy / DX = 2Y (3-y) Lim "x →∞" why is y = 3 y(4)=1 Why can we conclude that the limit is 3 instead of 0 when we don't understand the differential equation?