How large is the air conditioner for a 16 square meter room What brand of air conditioner is good

How large is the air conditioner for a 16 square meter room What brand of air conditioner is good

According to the cooling capacity of 200W per square meter,
The room of 16 square meters should use at least 3200W small 1.5p air conditioner
The principle of buying air conditioner is to buy large one instead of small one
Gree is the first choice for domestic brands, followed by Haier and Midea, with high cost performance;
Daikin is the first choice of imported brand frequency conversion, Mitsubishi Motor is the first choice of constant speed

Two times the square of a number is equal to seven times the number

2x^2=7x,
2x^2-7x=0,
x(2x-7)=0.
Ψ x = 0 or 2x-7 = 0
∴x1=0,x2=7/2.
So this number is equal to 0 or 7 / 2

Known: as shown in the figure, in △ ABC, ab = AC, BC = BD, ad = de = EB, then the degree of ∠ A is ()
A. 30°B. 36°C. 45°D. 50°

In the case of EBD (EBD = x °, and the "be = De,, \\\\\\\\\\\\\ \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\1

Given the function f (x) = x ^ 2-x + ainx (x ≥ 1), if a

f(x)=x^2-x+aInx
f'(x)=2x-1+a/x=(2x^2-x+a)/x
Consider 2x ^ 2-x + a = 0
X1 = [1 + radical (1-8a)] / 4
X2 = [1-radical (1-8a)] / 4
When x ≥ 1, a

If the circumcircle radius of a right triangle is 5 and the inscribed circle radius is 1, then the perimeter of the right triangle is

Method 1: if the hypotenuse is 10 and one right edge is x + 1, then the other right edge is 11-x, so the sum of three sides is 22, that is, perimeter = 22
Method 2: let two right angle sides be x and Y respectively. According to the tangent length theorem, all three sides are tangent lines of inscribed circle,
So (x-1) + (Y-1) = 10, then x + y = 12, plus hypotenuse 10, so the perimeter is 22

Let the complete set u = {X / X be a prime number not more than 20}, (CUA) intersection B = {7}, Cu (A and b) = {2,17}, a intersection (cub) = {3,5}, find the set a, B

U={2,3,5,7,11,13,17,19}
If (CUA) intersection B = {7}, then 7 belongs to B but not to a
If cub = {3,5}, then 3,5 belongs to a but not to B
Cu (A and b) = {2,17} then 2,17 does not belong to a or B
So:
A={3,5,11,13,19}
B={7,11,13,19}

The side edge length of straight prism abc-a1b1c1 is a, the bottom ABC is a right triangle, the angle ACB = 90 degrees, AC = 2BC, A1B, B1C, calculate the surface area of triangular prism

Let BC = x, then AC = 2x, ab = x * 5 ^. 5. Extend c'b 'to d so that b'd = A. connect a'B, BD, a'd. then be is parallel to CB', and BD = CB '. So angle a'bd is equal to the angle of a'B, CB', so angle a'bd = 90 degrees

The equation 2aX & # 178; - X-1 = 0 has exactly one solution in (0,1). Find the value range of real number a

Let f (x) = 2aX ^ 2-x-1
There are two situations
1: If f (0) > 0 and f (1) 1, the problem can be solved

Finding the indefinite integral of 1-x ^ 7 / X (1 + x ^ 7) DX

1-x^7/x(1+x^7)
=1-x^6/(1+x^7)
∫1-x^7/x(1+x^7)dx
=x-(1/7)∫d(x^7)/(1+x^7)
=x-(1/7)In|1+x^7|+C

Advance by arithmetic
1. A transport team transported a batch of goods. One third of the goods were transported on the first day, 75 tons on the second day, 20 tons less than 3 / 5 of the total of the previous two days on the third day, and 33 tons left. How many tons of the goods are there?
2. Add 4 to the denominator of a fraction to get 4 / 15. If you subtract 19 from the denominator, you get 6 / 11. What's the score?
Arithmetic. It's better to write ideas

1.(75+33-20+75*3/5)/(1-1/3-1/3*3/5)=285
2.4/15=24/90 6/11=24/44 90-44=46 46/(4+19)=2
24/2=12 4/15=12/45 45-4=41
The original score was 12 / 41