How to calculate indefinite integral for 1 / (x (x ^ 7 + 2) with the second substitution method?

How to calculate indefinite integral for 1 / (x (x ^ 7 + 2) with the second substitution method?

The second substitution method refers to the substitution of trigonometric functions, which is not applicable to the second substitution method. DX = (1 / 2) ∫ [(2 + X &;) - X &;] / [x (X &; + 2)] DX = (1 / 2) ∫ [1 / X - X &; / (X &; + 2)] DX = 1 / 2 * ∫ 1 / X DX - 1 / 2

How to calculate indefinite integral for 1 / (x ^ 2 + 1) ^ (3 / 2) with the second substitution method?

Let x = tant, then t = arctanx, DX = (sect) ^ 2 DT
Substituting ∫ (sect) ^ 2 DT / (sect) ^ 3 = ∫ costdt = Sint + C = x / (1 + x ^ 2) ^ (1 / 2) + C

When the equation 4x ^ 2 + 4mx + m ^ 2 + M-10 = 0 (M is a positive integer) of X has an integer root, how many is the value of M?

4x^2+4mx+m^2+m-10=0
(2X)^2+2m(2X)+m^2=10-m
(2X+m)^2=10-m
X = - 1 / 2 (m ± root (10-m)), and 0

The power problem of voltage and current correlation direction and non correlation direction
① When the current and voltage take the associated reference direction, the formula is: P = UI; when p > 0, it is the absorbed power; when P0, it is the emitted power; when p > 0, it is the absorbed power

One is right, two is wrong
The first floor link will be very detailed, 2 Formula P = - UI, because the minus sign has been added, so it is still the absorbed power when p > 0; P

If the fractional equation A / x + 1 = 1 about X has a solution and the solution is negative, then the value range of a is?
If x ^ 2-5x-2008 = 0, then the value of fraction (X-2) ^ 2 - (x-1) ^ 2 + 1 / X-2 is?
If xy = 1, the result of (x-1 / x) (y + 1 / y) reduction is?

1.a/(x+1)=1,x+1=1/a
x=1/a-1

Connect a bulb marked with "220v1000w" to the circuit of 220V, 180V and 230V respectively, and find out the actual power consumed by the bulb? (urgent)
1. Connect a bulb marked with "220v1000w" to the circuit of 220V, 180V and 230V respectively, and find out the actual power consumption of the bulb?

In the 220 V circuit, it is just the rated voltage of the 220 V 1000 W bulb, and the actual power consumed is 1000 W
In 180V and 230V circuits, r = U2 / P = 48.4 Ω is obtained from the formula of "220v1000w, P = U2 / R",
Then the formula P = U2 / R is used to substitute u = 180V and R = 48.4 Ω, and the actual power of 180V circuit is p = 669.4w
Using the formula P = U2 / R, substituting u = 230V and R = 48.4 Ω, we can get the actual power of 230V circuit is p = 1093w

3a^2b-2ab+2ab^2)/(ab)=?

The original formula = AB (3a-2 + 2b) / AB
=3a-2+2b

Because r = u / I, the resistance is proportional to the voltage and inversely proportional to the current

No. the resistance is the characteristic of the resistance itself. It is not affected by the applied voltage and the current passing through
So it is wrong to say that resistance is proportional to voltage and inversely proportional to current
We can say that when the voltage is constant, the current is inversely proportional to the resistance; when the current is constant, the voltage is directly proportional to the resistance

A cuboid room, 5.2 meters long, 3 meters wide, 6 meters. The lower part of its four walls is painted with 1.1 meters high light green paint (Windows 8 square meters)
A cuboid room is 5.2 meters long, 3 meters wide and 6 meters long. The lower part of its four walls is painted with 1.1 meters high light green paint. How many square meters are the painted areas? The upper part of the four walls and the roof are painted with white paint (the windows are 8 square meters, not painted), and how many square meters are the painted areas?

1、
Painted area
=2×（5.2×1.1+3×1.1）
=18.04 square meters
2、
2.6-1.1 = 1.5m
Apply white paint
=2×（5.2×1.5+3×1.5）+5.2×3-8
=32.2 square meters

Does the LED light strip consume electricity?

In fact, it's because they don't know the power and electrical parameters of LED light strips. For general LED light strips, the power per meter of 0603 is 1.5W, and that of 1210 is 4.8w, The power of 5050 LED light bar per meter is 7.2W. Even if the highest power consumption of 5050 LED light bar is 7.2W per meter and 8 hours per day, the daily power consumption is: 7.2W * 8h = 57.6wh, monthly power consumption: 57.6wh * 30 = 1728wh (1.728kwh, i.e. 1.728kwh) and annual power consumption: 1728wh * 12 = 20736wh (20.736kwh, i.e. 20.736kwh). If more LED light bars are used, the power consumption of 5050 LED light bar is higher than that of 5050 LED light bar, In fact, in the family, the daily utilization rate is not 8 hours, even if calculated according to 8 hours, the power consumption rate is almost negligible. Therefore, you can rest assured to use it. Don't install it during decoration, but dare not use it later, It's a waste of resources