Given x + 1 / x = 2, find X & # 178; + 1 / 2 of X

Given x + 1 / x = 2, find X & # 178; + 1 / 2 of X

(2) Given x + 1 / x = 2, find X & # 178; + 1 / 2 of X
X + x 1 / 2
Square on both sides
X & # 178; + 1 / 2 of X + 2 = 4
X & # 178; + 1 / 2 of x = 2

Calculation: (x + 1 / X & # 178; - x-x / X & # 178; - 2x + 1) △ 1 / X; a & # 178; - B & # 178; / AB ^ (1 / A-1 / b)

（x+1/x²-x-x/x²-2x+1）÷1/x
=[(x+1)/x(x-1)-x/(x-1)²】÷1/x
=(x+1)/(x-1)-x²/(x-1)²
=【(x+1)(x-1)-x²】/(x-1)²
=1/(x-1)²
a²-b²/ab÷(1/a-1/b).
=（a+b）（a-b）/ab÷（b-a）/ab
=-a-b
If you don't understand this question, you can ask,

If one third of the square - 2Y + 6 = 10, then x & # 178; - 6y=

The square of 3 / X - 2Y + 6 = 10
The square of X - 6y + 18 = 30
The square of x-6y = 30-12
The square of X - 6y = 18

What does r mean in physics?

In the circuit is resistance,
Gravity, in circular motion, is distance, radius
Too much
What are you asking about?

What's the n-th power of two thirds plus two ninths plus two 27th plus three

1-（1/3）^n

In the circuit, two lamps L1 and L2 are connected in parallel. Their resistances are 200 Ω and 400 Ω respectively. If the current through L1 is 0.5 A, what is the total current

The lamp is in parallel, the current through L1 is 0.5, the voltage at both ends is 0.5 * 200 = 100V, then the current of 400 Ω is 100 / 400 = 0.25A, then the total current is 0.25 + 0.5 = 0.75a

2. Multiple characteristics of 3,4,5,6,7,8,9

(1) If the last bit of an integer is 0, 2, 4, 6 or 8, then the number can be divided by 2
(2) If the sum of the numbers of an integer can be divided by 3, then the integer can be divided by 3
(3) If the last two digits of an integer can be divided by 4, then the number can be divided by 4
(4) If the last bit of an integer is 0 or 5, the number can be divided by 5
(5) If an integer can be divided by 2 and 3, then the number can be divided by 6
(6) If the number of digits of an integer is truncated, and then 2 times of the number of digits is subtracted from the remaining number, if the difference is a multiple of 7, then the original number can be divided by 7. If the difference is too large or it is difficult to see whether it is a multiple of 7 by mental arithmetic, the above process of "truncation, multiplication, subtraction and difference checking" needs to be continued until it can be clearly judged, The process of judging whether 133 is a multiple of 7 is as follows: 13-3 × 2 = 7, so 133 is a multiple of 7; for example, the process of judging whether 6139 is a multiple of 7 is as follows: 613-9 × 2 = 595, 59-5 × 2 = 49, so 6139 is a multiple of 7, and so on
(7) If the last three digits of an integer can be divided by 8, then the number can be divided by 8
(8) If the number sum of an integer can be divided by 9, then the integer can be divided by 9

Connect the lamp L in series with the resistor R and connect it to the power supply with a voltage of 10V. The bulb will light normally. The power consumed on the resistor R is 2W. The resistance RL of the lamp is 12 Ω and RL is greater than R. calculate the rated voltage of the lamp L?

The current of the circuit is: I = u / R, total = 10 / (12 + R)
According to: P = I ^ 2R
The power of the resistor is: 2 = [10 / (12 + R)] ^ 2 * r
Solve the equation: r = 18 or r = 8, choose r = 8 according to the meaning of the question
At this time, the circuit current: I = 10 / (12 + 8) = 0.5A
Lamp voltage: u = 0.5 * 12 = 6V
Rated voltage 6V

Given that the number corresponding to point a on the number axis is a, the number corresponding to point B is B, and | a + 4 | + (B-1) = 0, the distance between a and B is denoted as | ab |, which is defined as | ab | = | A-B |
(1) Find the length of line ab | ab |;
(2) Let the number corresponding to point P on the number axis be X. when | PA | - | Pb | = 2, find the value of X;

It should be (B-1) &
(1)
The sum of absolute and square terms is 0, and they are 0 respectively
a+4=0 a=-4
b-1=0 b=1
|AB|=|a-b|=|-4-1|=5
(2)
|PA|-|PB|=2
|x-(-4)|-|x-1|=2
|x+5|-|x-1|=2
When x ≥ 1, x + 5 - (x-1) = 26 = 2, the equation does not hold and X has no solution
-5≤x

An ammeter with a range of 100ua has an internal resistance of 100ohm, and the dial scale is even. Now a 9900ohm resistor is connected in series. If it is refitted into a voltmeter, the range of the voltmeter is several v

The full bias current is 100 μ a
According to Ohm's law, u = IR = 100 × 10 ^ - 6 * (100 + 9900) = 1V
So the range is 1V