There is a RL Series circuit, known r = 504, l = 12.7, the terminal voltage in the circuit is 220 v PS: the answer (1) impedance 6.71; impedance angle 36.5 （2）I=32.8A ； P=5.81 kW R = 504 ohm, l = 12.7mh,

There is a RL Series circuit, known r = 504, l = 12.7, the terminal voltage in the circuit is 220 v PS: the answer (1) impedance 6.71; impedance angle 36.5 （2）I=32.8A ； P=5.81 kW R = 504 ohm, l = 12.7mh,

Are you sure the title is correct or the answer is correct? Also, please mark the unit and the frequency

Given the set B = {x | - M + 1 is less than or equal to x, X is less than or equal to 2m-1}, a = {| - 2 is less than x, X is less than or equal to 5}, B is included in a, and the value range of M is obtained

B={x|-m+1

In △ ABC, ∠ ACB = 90 degrees, BD bisector ∠ ABC intersects AC at point D, De is the vertical bisector of AB, BD = 2DE, de = 1.5cm, find the length of AC

AC＝4.5cm
Because: De is the vertical bisection of AB, so ADB is an isosceles triangle, ad = BD = 2DE = 1.5 * 2 = 3 (CM)
In addition, BD = 2DE, so in RT △ BDE, ∠ DEB = 30 degrees, then ∠ DBC = 30 degrees
In RT △ DBC, ∠ DBC = 30 degrees, so CD = 1 / 2bd = 1.5 (CM)
So AC = AD + CD = 3 + 1.5 = 4.5 (CM)

If the main argument value of complex number (1 + AI) ^ 2 is π / 4, then the value of real number a is π / 4

Because (1 + AI) ² = 1-A & #178; + 2ai = (A & #178; + 1) (COS π / 4 + isin π / 4) = [√ 2 (A & #178; + 1) / 2] (1 + I), and,
So 1-A & # 178; = 2A = √ 2 (A & # 178; + 1) / 2, the solution is a = - 1 + √ 2

Let the circle C1: x ^ 2 + y ^ 2-10x-6y + 32 = 0, the moving circle C2: x ^ 2 + y ^ 2-2ax-2 (8-A) y + 4A + 12 = 0, let p be the point on the ellipse x ^ 2 / 4 + y ^ 2 = 1, let p be a tangent of circle C1, let T1 be the tangent, let p be a tangent of circle C2, let T2 be the tangent. Question: is there any point P1 that makes infinite number of circles C2 satisfy pT1 = pT2? If it exists, find all such points P; if it does not exist, explain the reason

The relationship between the formation point and the center of a circle, C1-C2 = 0 (why) there are 2 (x-y-2) a-10x-6y + 36 = 0. This equation is constant. There are X-Y = 2, 10x + 6y = 36. X = 3, y = 1. If we substitute it into the naked circle equation, we know whether it is true or not

Finding indefinite integral ∫ 1 / (1 + 2x) &# 178; DX ∫ X / √ x &# 178; + 4 DX

1/4*Ln(2x+1)+1/(4(2x+1))
√(x²+4)

English translation
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as time goes by, the sources of information has become more and more varied, and my favorite in which is the internet. firstly, the internet shows us things that happened thounsands of miles away, even if there was a long distance between us, we could still get to know each other; secondly, we could learn all the things we want over it without even going anywhere. we wouldn't need to look up for information in the library any more, that saves us a huge amount of time. thirdly, its provides the thoroughest knowledge , anything u want , u can always find it there

Solve the following equation by factorization
（x+1)²=（2x-1)²
（2-3x)+(3x-2)²
4x(3x+1)=3x+1
The second question is wrong
（2-3x)+(3x-2)²=0

1.(x+1)^2-(2x-1)^2=0
(x+1+2x-1)(x+1-2x+1)=0
3x(2-x)=0
x1=0;x2=2
Did you write the equal sign as a plus sign?
(2-3x)-(2-3x)^2=0
(2-3x)(1-2+3x)=0
(2-3x)(3x-1)=0
x1=2/3;x2=1/3
3.4x(3x+1)-(3x+1)=0
(3x+1)(4x-1)=0
x1=-1/3;x2=1/4

What does x stand for? How to calculate the area of a square or rectangle? What does each letter stand for?

X is an unknown number. Let X be an unknown number
Square area formula: S = a * a, used when calculating area with known side length; a is side length
Rectangle area formula: S = a * B, used when calculating area with known side length; a is length, B is width
S is the area

The domain of the function y = lgx
The answer is right

As long as the true number is greater than 0
That is x > 0
The domain is (0, + OO)