Given a = log20.3, B = 2 ^ 0.3, C = 0.3 ^ 0.2, the order of ABC from large to small is______

∵a=log2^0.3 ∴a∈（-∞,0）
∵b=2^0.3 ∴b∈(0,1)
∵c=0.3^0.2 ∴c∈(1,+∞)
∴ a＜b＜c

If the value range of function y = loga (AX2 + X + a) is r, then the value range of a is y = log2 (AX2 + X + a) and the definition field is r, then the value range of a is r
If the value range of function y = loga (AX2 + X + a) is r, then the value range of a is r
If the definition field of y = loga (AX2 + X + a) is r, then the value range of a is

Y = L0g a (AX ^ 2 + X + a) first of all, if the base of logarithmic function a > 0 and a ≠ 1, let g (x) = ax ^ 2 + X + ay = log a (g (x)) be r, then G (x) must cover (0, + ∞) ∵ a ≠ 0, G (x) is a quadratic function, it must be open up and have at least one intersection with X axis: a > 0, and the discriminant = 1 ^ - 4A ^ 2 ≥ 0, that is - 1 / 2 ≤ a ≤ 1 /

Known cylinder height: 0.35, diameter: 0.27, weight: 50kg, calculate density

Let's calculate the volume first. Density equals mass divided by volume. V = (0.27 / 2) ^ 2 * π * 0.35 density d = 50 / v. you can calculate the answer yourself

The simple method is used to calculate 28.5 × 1.3-85 × 0.130.435 × 16 + 56.5 times 0.16
Hand it in tomorrow, quick
The above error is 28.5 × 1.3-85 × 0.130.435 × 16 + 56.5 × 0.16

28.5×1.3-85×0.13
＝28.5x1.3-8.5x1.3
=1.3x(28.5-8.5)
=1.3x20
=26
0.435×16+56.5x0.16
=0.435x100x0.16+56.5x0.16
=0.16x(43.5+56.5)
=0.16x100
=16

If a primitive function of F (x) is LNX, then f '(x)=

A primitive function of F (x) is LNX
So f (x) = (LNX) '= 1 / X
So f '(x) = - 1 / X & sup2;

How much oxygen does a cubic meter of air contain and how much carbon is needed to burn it?

Assuming the standard condition, the volume content of oxygen in the air is about 20.95%, then 1 cubic meter of air contains 209.5 liters of oxygen, and the amount of converted material is 9.353 moles. If carbon is completely burned, it will take 9.353 moles and 112.236 g of carbon to generate CO2. If all carbon is generated, it will take 18.706 moles and 224.472 G

If for any non-zero rational numbers a and B, the operation $is defined as follows: a $B = B / A-2, then what is the value of (- 6) $2? What is the value of (- 6) $2 $1?

Because a $B = B / A-2
So (- 6) $2 = 2 / (- 6) - 2 = - 7 / 3
（-6）$2$1=[（-6）$2]$1=(-7/3)$1=1/(-7/3)-2=-17/7

Find the volume of the part of the sphere x + y + Z ＜ = R between the plane z = A and z = b! 0
Is x square plus y square plus Z square less than or equal to R square

V = ∫ [a, b] π (R & sup2; - Z & sup2;) DZ = (π / 3) (B-A) (3R & sup2; - B & sup2; - A & sup2; - AB) [rotary body slice method]

"Light year is a unit of length used in astronomy. It represents the distance that light travels in a vacuum for one year: how many kilometers is a light year? Vega, the star closer to us, is about 27 light-years away from the earth. How many kilometers is Vega away from the earth?

The distance of light propagation in a year: S = VT = 3 × 108m / s × 365 × 24 × 3600s ≈ 9.46 × 1015m = 9.46 × 1012km; the distance between Vega and the earth: s' = s × 27 = 9.46 × 1012km × 27 ≈ 2.55 × 1014km. A: one light year equals 9.46 × 1012km; Vega is 2.55 × 1014km away from the earth

During the northern and Southern Dynasties, the mathematician of our country [] made the PI accurate to the seventh place after the decimal point, which was more than 1000 years earlier than that of Europe?

Zu Chongzhi, a mathematician in the northern and Southern Dynasties of China, put pi to the seventh decimal place, which was more than 1000 years earlier than that in Europe

Given a = log20.3, B = 2 ^ 0.3, C = 0.3 ^ 0.2, the order of ABC from large to small is______