Cylindrical wood, 150 cm long, cross-section diameter is 12 cm, if according to the ratio of 2:3 according to it into two sections, then the shorter section volume is how many cubic centimeters?

The shorter one is two fifths of 150, 60 cm in length and 6 cm in radius
So the volume of the shorter section is 3.14 * 6 * 6 * 60 = 6782.4 cubic centimeter

How many cubic centimetres of wood do you want to cut into the biggest cone when you cut a section of cylindrical wood with a bottom diameter of 12 cm and a height of 15 cm?
I need an answer before 2 o'clock

First calculate the cylinder volume v = sh = 3.14 * 6 * 6 * 15 = 1695.6 (cubic centimeter)
Then the volume of cone with the same height and the same bottom is v = SH / 3 = 1695.6 / 3 = 565.2 (cubic centimeter)
The truncated volume is 1695.6-565.2 = 1130.4 (cm3)

A kind of wood has a cross-sectional area of 2.25dm2 and a length of 30dm. How many cubic decimeters is the volume of this wood? How many cubic meters is it

2.25 × 30 × 200 = 13500 (cubic decimeter)
13500 cubic decimeters = 13.5 cubic meters
A: slightly

The result of factoring polynomial (x ^ 2-2x) ^ 2-2x ^ 2 + 4x-3 is
（x^2-2x）^2-x^2+2x-2=(x^2-2x）^2-( )-2=(x-1)^2(_____ )

（x^2-2x）^2-2x^2+4x-3=（x^2-2x）^2-2(x^2-2x)-3=(x^2-2x-3)(x^2-2x+1)=(x-3)(x+1)(x-1)^2（x^2-2x）^2-x^2+2x-2=(x^2-2x）^2-(x^2-2x)-2==(x^2-2x+1)(x^2-2x-2)=(x-1)^2(x^2-2x-2)

Given that the two intersections of the circle x ^ 2 + y ^ 2 + x-6y + 3 = 0 and the straight line x + 2y-3 = 0 are p and Q, the equation of the circle with the diameter of line segment PQ is obtained

x^2+y^2+x-6y+3=0
(x+1/2)²+(y-3)²-(1/2)²-9+3=0
(x+1/2)²+(y-3)²=25/4
Center (- 1 / 2,3) radius 5 / 2
x+2y-3=0
x=3-2y
(3-2y+1/2)²+(y-3)²=25/4
(7/2)²-2y*2*7/2+(-2y)²+y²-6y+9=25/4
5y²-20y+15/2=0
y=2+(√10)/2 y=2-(√10)/2
x=-1-√10 x=-1+√10
Midpoint coordinates of PQ (- 1,2)
|QP|=5√2 (5√2/2)²=25*2/4=25/2
The equation of the circle whose line segment PQ is diameter: (x + 1) &# 178; + Y-2) &# 178; = 25 / 2

If a is greater than the absolute value of B, then a + B = () 0. If the absolute value of a is greater than a, then a is a () number, if the absolute value of x minus the square of one + 2Y + 11 = 0, x + y
If a is greater than the absolute value of B, then a + B = () 0
If the absolute value of a is greater than a, then a is a () number
If the absolute value of x minus the square of one + 2Y + 11 = 0, then x + y = ()

If a is greater than the absolute value of B, then a + B = (greater than) 0
If the absolute value of a is greater than a, then a is a (negative) number
If the absolute value of x minus the square of one + 2Y + 11 = 0, then x + y = ()

Given function f (x) = x2 + 2x. (I) sequence {an} satisfies: A1 = 1, an + 1 = f ′ (an), the general term formula of sequence {an}; and the general term formula of sequence {BN} with the first n terms and Sn (II) known sequence {BN} satisfying B1 = t ＞ 0, BN + 1 = f (BN) (n ∈ n *)

(I) ∵ f (x) = x2 + 2x, ∵ f ′ (x) = 2x + 2, ∵ an + 1 = f ′ (an) = 2An + 2, ∵ an + 1 + 2An + 2 = 2, and a1 + 2 = 3, ∵ sequence {an + 2} is an equal ratio sequence with 3 as the first term and 2 as the common ratio, ∵ an + 2 = 3 × 2N-1, ∵ an = 3 × 2n-1-2; ∵ Sn = a1 + A2 + +an=3（1+2+22+… +The 2n-1-2n-2n-2n-2n-2n-2n-2n-2n-2n-2n-3 (Ⅱ) \\\\\\\2n-1-2n-1-2n = 3 × 1-2n-2n-2n-2n-2n-2n-2n-2n-2n-2n-2n-3-3. (Ⅱ) \\\\\\\\\\\\\\\\\\\\\\\\\\\\\= LG (T + 1) 2n − 1, ∩ BN + 1 = (T + 1) 2n − 1, ∩ BN = (T + 1) 2n − 1-1 ．

Let X have probability density (distribution density function), - ∞ + ∞ and find the probability density (distribution density function) of y = x ^ 2

The distribution functions of X and y are f (x) and f (y), and the probability density of random variable x is f (x)
First, find the distribution function f (y) of Y
Because y = x ^ 2 > = 0, when Y0, there is
F(y)=P{Y

If f (x) = cos (x + φ) (x ∈ R) is an even function, then=

K π (k belongs to Z)

It is proved that the product of odd function f (x) and odd function g (x) is even function

Let H (x) = f (x) g (x)
Then H (- x) = f (- x) g (- x)
=[-f(x)][-g(x)]
=f(x)g(x)
=h(x)
So it's an even function

Cylindrical wood, 150 cm long, cross-section diameter is 12 cm, if according to the ratio of 2:3 according to it into two sections, then the shorter section volume is how many cubic centimeters?