In physics, Z is called the complex impedance of RLC series circuit,

In physics, Z is called the complex impedance of RLC series circuit,

R is short for resistance,
L is inductance,
C is the abbreviation of capacitance

Calculation method of current (series and parallel connection,

The most basic formula derived from Ohm's law I = u / R is no nonsense
1 series circuit: itotal = I1 = I2 (in series circuit, the currents are equal everywhere) utotal = U1 + U2 (in series circuit, the total voltage is equal to the sum of the voltages at both ends of each part) rtotal = R1 + R2 + R3... + RN U1: U2 = R1: R2 (in series to form a positive ratio voltage) P1 / P2 = R1 / r2 when n constant resistors R0 are in series, the total resistance R = NR0
2 parallel circuit: iton = I1 + I2 (in parallel circuit, the main circuit current is equal to the sum of each branch current) uton = U1 = U2 (in parallel circuit, the power supply voltage is equal to the voltage at both ends of each branch) 1 / rton = 1 / R1 + 1 / R2 I1: I2 = R2: R1 (parallel inverse ratio shunt) rton = R1 · R2 (R1 + R2) rton = R1 · R2 · R3: (R1 · R2 + R2 · R3 + R1 · R3) that is, 1 / rton = 1 / R1 + 1 / r2 + +1 / RN P1 / P2 = R2 / R1 when there are n fixed value resistors R0 in parallel, the total resistance R = R0 / N, that is, the total resistance is less than any branch resistance, but the more parallel the total resistance is, the smaller the total resistance is
Finally, I would like to say that: the formula combined with the circuit diagram is basically not a big problem

In the triangle ABC, a = 4, B = 6, C = 120 °, find the value of sina
The answer is √ 57 / 19, which I don't think is right.

Cos C = A & # 178; + B & # 178; - C & # 178; / 2Ab calculates C = 2 radical 19, then a / Sina = C / sinc calculates Sina = radical 57 / 19

If the sum of the remainder, divisor, quotient and remainder is 56, what is the divisor equal to?

Let the divisor be x, according to the meaning of the question: 4x + 1 = 56-x-4-1 & nbsp; & nbsp; 5x = 50 & nbsp; & nbsp; X = 10, that is: the divisor is 10, then the divisor is 56-10-4-1 = 41, a: the divisor is 41

As shown in the figure, it is known that AB is the diameter of the circle O, CD is the chord, AB is perpendicular to e, of is perpendicular to AC, F, be = of
As shown in the figure, it is known that AB is the diameter of circle O, CD is the chord, AB is perpendicular to e, of is perpendicular to A. prove: of parallel BC △ AFO is equal to △ CEB, if EB = 5, CD = 10 root sign 3, let OE = x, find the value of X and the area of shadow part

It is proved that: in the triangle ABC, AB is the diameter, C is the point on the circle, so the angle ACB = 90, that is, BC is perpendicular to acof, and AC is perpendicular, so of is parallel. BC ∵ ab ⊥ CD ∥ CE = 1 / 2CD = 5 √ 3cm. In the right angle △ OCE, OC = ob = x + 5 (CM). According to the Pythagorean theorem, we can get the solution of (x + 5) ^ 2 = (5 √ 3) ^ 2 + x ^ 2: x = 5 ∥ Tan ∠ Co

Answer by factoring polynomials. There must be a process 17 × 3.14 + 61 × 3.14 + 22 × 3.14

17×3.14+61×3.14+22×3.14
=3.14×（17+61+22）
=3.14×100
=314

In △ ABC, ab = AC, ∠ 1 = 1 / 2 ∠ ABC, ∠ 2 = 1 / 2 ∠ ACB, BD and CE intersect at point 0. As shown in the figure, what is the relationship between the size of ∠ BOC and the size of ∠ a? If ∠ 1 = 1 / 3 ∠ ABC, ∠ 2 = 1 / 3 ∠ ACB, what is the relationship between ∠ BOC and ∠ a? If ∠ 1 = 1 / N ∠ ABC, ∠ 2 = 1 / N ∠ ACB, what is the relationship between ∠ BOC and ∠ a?

Extend Bo AC to D1, ∵ Bo bisection ∵ ABC ∵ ABO = 1 / 2 ∵ ABC ∵ BDC = ∵ a + ∵ ABO = ∵ a + 1 / 2 ∵ ABC ∵ co bisection ∵ ACB ∵ ACO = 1 / 2 ∵ ACB ∵ BOC = ∵ BDC + ∵ ACO = ∵ a + 1 / 2 (∵ ABC + ∵ ACB) ∵ ABC + ∵ ACB = 180 - ∵ a ∵ BOC = ∵ a + 1 / 2 (180 - ? a) ?

90°13〃-57°21′44〃

90°13〃-57°21′44〃
= 32°38′29〃

What is the determinant of the inverse matrix of the product of two square matrices A and B
For invertible matrices A and B of order n, how can we get that det [(AB) ^ (- 1)] equals [1 / deta ^ (- 1)] * [1 / DETB ^ (- 1)]
I just started to study linear algebra. According to your first statement, why is it not equal to det (a inverse) * det (b inverse), but equal to the product of their reciprocal? Beginners of linear algebra ideas can not open, please forgive me!

The inverse of AB = B, inverse * a, both sides of the inverse take det at the same time. From any two square matrices C and D, DET (CD) = det (c) * det (d) holds, the result holds. Of course, since det is a number, the commutative law of multiplication holds
Another understanding (if you don't admit the above C D theorem for the time being)
Since it is invertible, there must be (I (R)) left multiplied by finite row transformations and right multiplied by finite column transformations
Those who have learned the same solution deformation of linear equations all know that they do not change rank, and then they can know that both sides are true by taking det at the same time

52 divided by 3 equals

More than 17
51/3
17.3333……