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How do four fives equal seven
5+(5+5)/5=7
As shown in the figure, the area of parallelogram ABCD is 40 cm 2
Because the shadow area is 14 times of the parallelogram area, then 40 × 14 = 10 (square centimeter); answer: the shadow area is 10 square centimeter
The point P (m, 1) is on the image of the inverse scale function y = x / K. he finds the analytic expression of the inverse scale function on the image of the linear function y = - x + 3 with respect to the y-axis symmetric point
His point of symmetry about the y-axis is (- m, 1) at y = - x + 3
Then 1 = - M + 3
m=2
So 1 = m / K
k=m=2
So y = x / 2
Given that f (x) is a quadratic function, f (0) = 2, and when x = 1, f (x) has the minimum value of - 1, the analytic expression of F (x) is obtained
When x = 1, f (x) has a minimum value of - 1,
Let f (x) be analytic: F (x) = a (x-1) & # 178; - 1
F (0) = 2 is substituted into 1
a-1=2
a=3
Therefore, the analytic expression of F (x) is: F (x) = 3 (x-1) & # 178; - 1
That is, f (x) = 3x & # 178; - 6x + 2
The waist length of an isosceles right triangle is 50 decimeters, so its area is () square decimeters
50 * 50 / 2 = 1250 square decimeters
a. B is two points on the hyperbola xy = k, the abscissa of a and B are 1 and 2 respectively, the extension line of line AB intersects X axis at point C, and the area of triangle AOC is 6
a. B is two points on the hyperbola xy = K. the abscissa of a and B are 1 and 2 respectively,
A（1,k)B(2,k/2)
The equation of line AB is (Y-K) / (x-1) = (K / 2-k) / (2-1)
Let y = 0 be substituted into C coordinate (3,0)
The area of triangle AOC is 6 = 1 / 2 * 3 * K
The solution is k = 4
The derivation of y = ln Tan (x / 2) - cosx * ln TaNx; arctan (x + 1 / x-1)
Hurry! Fill in the blanks with reduplicated words
A (bright) mirror
() face () star () sky
A knock on the door
() the sound of running water () the sound of trumpets () the sound of gongs
() the sound of walking () the sound of whistles () the sound of bells
A (bright) mirror
(red) face (shining) star (blue) sky
A knock on the door
(Hua Hua Hua Hua) the sound of running water (ba ba ba ba) the sound of trumpet (Dangdang Dang) the sound of Gong
(rustling) the sound of walking (rustling) the sound of whistles (banging) the sound of bells
In the rectangular coordinate system, a (radical 2,4) B (0, - 2 radical 2) 0 is the origin to calculate the area of the triangle AOB
According to the distance formula between two points, the distance between two points AB is calculated, and then the distance between OA and ob is calculated according to Pythagorean theorem, and then calculated by Helen's formula s = √ P (P-A) (P-B) (P-C). Where p = 1 / 2 (a + B + C), a, B and C are the lengths of three sides respectively
It's up to you to do the calculation!
I wish you a happy study!
It is known that a, B and C are the lengths of three sides of triangle BC, and the quadratic function y = (a + b) x2 + 2cx - (a-b). When x = - 1 / 2, the function has the minimum value - B / 2
Try to judge the shape of triangle
The axis of symmetry is x = - C / (a + b) = - 1 / 2
a+b=2c
y=2cx²+2cx-(a-b)
=2c(x+1/2)²-c/2-(a-b)
Minimum = - C / 2-A + B = - B / 2
c=3b-2a
So a + B = 2C = 6b-4a
5a=5b
a=b
If a + B = 2c, then 2A = 2c, a = C
So a = b = C
So it's an equilateral triangle
RELATED INFORMATIONS
- 1. Given that ab ≠ 0, the sufficient and necessary condition for a + B = 1 is A3 + B3 + ab-a2-b2 = 0
- 2. Fairy tale composition
- 3. (it's better to understand. X is the death of Ike and X is the multiply sign) judge 1. 16x = 0 is the equation () 2. The number 5 less than x is 10, and X is 10 () 3. When x is reduced by 25%, it is equal to 3 / 4 of 300. X is 300 () 4. When solving the equation 3x + 5 / 4 × 2 = 13 / 3, we should first consider 3x as an additive () 5. A car travels an average of M kilometers per hour, a bicycle travels an average of N kilometers per hour (n < m), and the distance difference is 4 (m-n) kilometers () solve equations x+48=72 2x-5=25 0.15x=0.9 9÷5x=12 4x+36=56 10=31-3x 1.7×(12-x)=5.1 (135 + 49) △ x = 23.4% 1 (x + 0.25) = 45% Practical questions 1. The school chorus has 124 people, 19 more than three times the number of science and technology groups. How many people are there in the school science and technology groups? 2. After 2.5 hours of driving on a 360 km long road, there are 210 km left. How many kilometers does the car travel per hour?
- 4. The known set a = {x | x > 15, or X
- 5. As shown in the figure, the circumscribed circle diameter ab of △ ADC intersects CD at point e. it is known that ∠ C = 65 ° and ∠ d = 47 ° and the degree of ∠ CEB is calculated
- 6. In space rectangular coordinate system, equation 3x-4y-12z-14 = 0 represents plane, P (0,0,1) represents point By analogy with the formula of the distance from the midpoint to the straight line in the plane rectangular coordinate system, we can get that the distance from the point P to the plane is
- 7. It is known that the center of the ellipse C is at the coordinate origin, the focus is on the y-axis, and the eccentricity is √ 2 / 2. Take one vertex and two focuses of its minor axis as the vertex, and the triangle area = 0.5 1) Solving elliptic equation 2) If there are two points a and B, which are the intersection and difference between the line L passing through the point P (0, m) and the ellipse, and satisfy AP vector = λ Pb vector, OA vector + λ ob vector = 4op vector, calculate the value of λ and the value range of M
- 8. It is known that the expanded side view of a cone is a semicircle, and the ratio of its side area to its bottom area is calculated Try to explain it to me. I can't understand the answer like this The length of conical generatrix L and the radius of bottom R Conical generatrix length = developed circle radius = L Base circumference = 2 * pi * r = arc length of expanded circle = pi * l r=L/2 Side area s' = pi * L * L / 2 Bottom area s = pi * r * r S':S=1:2 Or such an answer Side area = expanded area = C (bottom perimeter) XL / 2 = 2 x R (bottom radius) XL / 2 And C = pie XL = 2 pie XR, i.e. L = 2R So the side area is 2 x R ^ 2 Bottom area = x R ^ 2 So the final result is 2:1
- 9. The equation x ^ 4 + (2m + 1) x ^ 3 - (3m-3) x ^ 2 - (5m + 17) x + (6m + 14) = 0 has four solutions, and only two of them are equal, so we can find the value of M Sorry, it's x ^ 4 + (2m-1) x ^ 3 - (3m-3) x ^ 2 - (5m + 17) x + (6m + 14) = 0
- 10. 60% of the number a is 2.5 more than 25% of 32. What's the number a? (solve the equation)
- 11. Find ∫ ∫ [1 / (x ^ 2 + y ^ 2 + 1)] dxdydz, where D is a closed region bounded by cone x ^ 2 + y ^ 2 = Z ^ 2 and plane z = 1
- 12. Sequence 2, - 11101, - 100110001 A general formula of is?
- 13. A cylindrical reservoir with a bottom radius of 10 meters can store 1256 cubic meters of water. If the depth of the reservoir is 1.5 meters, how much can it store?
- 14. How much is the length and width of a rectangular vegetable field? Solve the equation
- 15. Let b > a > 0 be a constant and f (x) = 2x-x ^ 2. It is known that when x belongs to [a, b] and the range of F (x) is [1 / B, 1 / a], the values of a and B can be obtained
- 16. a> 0, b > 0, C | B | > | a |, is to compare the size of ABC, a + B, a + C, B + C Compare the size of a, B, C, a + B, a + C, B + C
- 17. A rectangular playground, its perimeter is 250 meters, length and width ratio is 3:2, the playground area is how many square meters?
- 18. A number must be bigger than its reciprocal
- 19. 9801 * 99 simple calculation, recursive equation
- 20. Several super simple fraction problems (as long as the formula) 1. A grain store buys 80 tons of rice, the flour is one fifth less than rice, how many tons of flour? 2. A grain store buys 64 tons of flour, the flour is one fifth less than rice, how many tons of rice? 3. A grain store buys 16 tons less than rice, the flour is one fifth less than rice, how many tons of rice?