A piece of irregular stone was submerged in a rectangular glass tank 5 decimeters long and 4 decimeters wide. It was measured that the water surface rose 5 cm. What is the volume of this stone

A piece of irregular stone was submerged in a rectangular glass tank 5 decimeters long and 4 decimeters wide. It was measured that the water surface rose 5 cm. What is the volume of this stone

First calculate the volume of the cuboid glass water tank, then calculate the volume of the glass water tank rising 5 cm, and finally the volume of this stone

There is a cuboid glass tank, 3 decimeters long and 2 decimeters wide. After putting an irregular stone, the water depth is 1. After being fished out, the water surface drops by 0
What is the volume of this stone,

When the stone is in water, the volume of water plus stone is 3 x 2 x 1.5 = 9 cubic decimeters
When the stone is removed, the volume of water is 3 x 2 x 0.5 = 3 cubic decimeters
So the volume of the stone is 9 - 3 = 6 cubic decimeters

Take a point P on the image of the function y = - 3x, pass through the point P and make the vertical X axis of PA. if the abscissa of the point P is known to be - 2, then the area of the triangle POA (o is the origin of the coordinate) is______ ．

When x = - 2, y = - 3 × (- 2) = 6, the coordinates of point P are (- 2,6), PA = 6, OA = | - 2 | = 2, s △ POA = 12 × PA × OA = 12 × 6 × 2 = 6

The function f (x) defined on R satisfies that f (x + y) = f (x) + F (y) + 2XY, its axis of symmetry x = k, and when x = 1, the function obtains the extremum, and the analytic formula of the function is obtained!

Substituting x = 0, y = 0 to get f (0) = 2F (0) f (0) = 0
Y = - x to get f (0) = f (x) + F (- x) - 2x ^ 2 F (x) + F (- x) = 2x ^ 2 (1)
F (x) = f (2k-x) let y = 2K, x = - x, f (2k-x) = f (- x) + F (2k) - 4kx, that is, f (x) = f (- x) + F (2k) - 4kx (2)
(1) + (2) 2F (x) = 2x ^ 2-4kx + F (2k)
f(x)=x^2-2kx+f(2k)/2
And when x = 1, the function gets the extremum, even if the symmetry axis X = k = 1
So f (x) = x ^ 2-2x + F (2) / 2
And f (0) = 0
f(2)=0
The analytic expression of the function is f (x) = x ^ 2-2x

What idioms does Mao have

Nitpicking
Volunteer
Creepy
It's rare
Drinking blood
The wild goose has been plucked
A drop in the bucket
Goose feather for thousands of miles
Nothing
Barren land
The wool comes out of the sheep
Lighter than a feather
Burning eyebrows
Love feathers
The horse is thin and hairy
There are so many
It's a trifle
Careless hands and feet
Eyebrows and moustaches
It's snowy
Light as a feather
Cutting hair and washing marrow
It's a fine rain
Hongmaotai mountain
Love hair but not fur
It's a little scary
Rabbit horn and tortoise hair
Horse hair Hedgehog
the feather is not yet fully grown

(1) 3 (X-Y) ^ 2-9 (X-Y) - 8 (X-Y) ^ 2 + 6 (X-Y) - 1 (2) 2 (a + b) - 5 / 8 (a + b) ^ 2-2 / 3 (a + b) + 3 (a + b) ^ 2 + 2

3(x-y)^2-9(x-y)-8(x-y)^2+6(x-y)-1
=-5(x-y)^2-3(x-y)-1
2(a+b)-5/8(a+b)^2-2/3(a+b)+3(a+b)^2+2
=19/8(a+b)^2-4/3(a+b)+3(a+b)^2+2

Inequality solution: 2aX ≥ 3A * 2-2a x ∈ [a, ∞) is constant and the range of a is obtained
If 2aX ≥ 3A * 2-2a x ∈ [a, ∞) holds, the range of a is obtained

If a = 0
A = 0 is obviously true
If a > 0, then the original formula is changed to x > = 3A / 2-1, and X ∈ [a, ∞) is constant, so only a > = 3A / 2-1 is needed, that is a

We usually go to the library to read English books after school

We often go to library to read English books after class.

If the positions of rational numbers a and B on the number axis are shown in the figure, what is the value of A-B / A + B
Picture:_______ -1___ a_____ 0_________ 1____ b____
If it is less than 0, how do you calculate it,
Now please vote, just. Please don't vote,
Thank you, too

A is a number less than - 1, for example - 0. Several, B is a positive number greater than 1, A-B is a negative number, a + B because the absolute value B is larger than a, so a + B is a positive number, then their division must be a negative number less than 0

Given the function f (x) = x & # 178; + BX (B ∈ R), if | f (x) | ≤ 1 is constant in the interval (0,1), then the value range of B is

|f(x)|≤1
-1≤f(X)≤1
-1≤x²+bx≤1
In the interval (0,1]
F (0) = 0
-1≤f(-b/2)≤1
-1≤-b^2/4
-2≤b≤2