Use several plane figures to encircle a three-dimensional figure. Plane figures should use at least () plane figures?

Use several plane figures to encircle a three-dimensional figure, and at least (4) plane figures should be used

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1. To find the volume of a body of Revolution: a body of revolution formed by a curve (the square of y = x) and a figure surrounded by y = x rotating around the X and Y axes respectively? $(acontent)
2. Find the volume of the body of revolution formed by the plane figure surrounded by the curve y = x square and x = 3 rotating around the X axis
3. The volume of the body of revolution is obtained when the plane figure enclosed by the line y = √ (x-1), x = 4 and y = 0 rotates around the x-axis Review is urgent,
4. The volume of the body of revolution is () A. 8π3B. 10π3C. 6π3D. 32π3
5. A plane figure D is surrounded by a curve y = e ^ x, a straight line y = e, and a Y-axis. How to find the body of rotation formed by a rotation of plane D around the y-axis
6. Find the volume of the body of revolution formed by a section of arc of hyperbola x ^ 2 / 4-y ^ 2 / 9 = 1 in [2,5] and the plane surrounded by x = 5 rotating around the X axis
7. Find the area of the figure enclosed by the parabola y = x ^ 2 and y = 2x ^ 2, and find the volume of the solid figure formed by the figure rotating around the X axis
8. Find the area of the figure surrounded by X & # 178; + Y & # 178; = 2, X & # 178; + Y & # 178; = 4x, y = x, y = 0
9. As shown in the figure, in the plane rectangular coordinate system, the parabola y = - 1 / 2x & # 178; + 3 / 2x + 2 intersects X axis at two points a and B, and intersects Y axis at point C (1) ABC is a right triangle (2) : the straight line x = m (0 ∠ m ∠ 4) moves on the line ob, intersects the x-axis at point D, intersects the parabola at point E, intersects BC at point F. when m = what, EF = DF? (3) : after connecting CE and be, "is there a point e to maximize the area of triangle BCE?" if there is a point E, calculate the coordinates of point E and the maximum area of triangle BCE
10. It is known that parabola y ^ 2 = 2px (P > 0) and hyperbola x ^ 2 (radical 2-1) ^ 2-y ^ 2 / b ^ 2 = 1 have the same focus F, point a is the focus of two curves, and AF is vertical On the x-axis, the line L and the parabola intersect at two different points c, D If the vector OC * od = m (M is a constant) and the line l only passes through a unique point, the value of M and this point can be obtained
11. Xiao Ming wants to encircle the city with iron wire. If he wants to make the triangle area 30 square meters, how long is the iron wire? Just list the equation
12. Find the area of the plane figure surrounded by the following curve X = √ X and the line y = 0, x = 1, x = 2
13. Use three 6.28-meter-long iron wires to encircle the city, rectangular, square and round. Which figure has a large area? Let's make it clear
14. Use 24 cm long wire to circle the learned plane figure. Which figure has the largest area?
15. Use 96cm long wire to encircle a rectangular frame. The ratio of length, width and height of the cuboid is 5:2:3. How many centimeters are the length, width and height of the cuboid
16. As shown in the figure is the expansion of a cuboid, calculate the surface area and volume of the enclosed cuboid. (unit: decimeter)
17. The unfolded drawing of a cuboid may not be able to encircle the cuboid,
18. The three-dimensional figure of () besieged city of the cuboid
19. F (2x) = LNX, f (x) = lnx-ln2, how does the first step change into the second step!
20. If f (xn) = LNX, then the value of F (2) is () A. ln2B. 1nln2C. 12ln2D. 2ln2