![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
By using the collocation method, the quadratic equation of one variable X & # 178; - 4x-2 = 0 is transformed into the form of (a + b) &# 178;, then the root of the equation is
x²-4x-2=0
x²-4x＝2
x²-4x+4＝2+4
(x-2)²=6
x-2=±√6
x=2±√6
∴x1=2+√6, x2=2-√6.
RELATED INFORMATIONS
- 1. What's the meaning of "Oh, Miguel" in mathematical symbols
- 2. Solving the equation x & # 178; - X-1 = 2 / X & # 178; - x Such as the title
- 3. Power consumption on refrigerator: (kWh / 24h) 0.66 Is it 0.66 degree in one hour or 0.66 degree in 24 hours?
- 4. How to calculate the problem of 1002 & # 178; - 1002 * 4 + 4?
- 5. What is the current passing through the bulb marked with "220V 40W" in normal operation? What is the resistance in normal lighting
- 6. Simple operation 7 / 3 * 15 / 14 * 8 / 5
- 7. If the two fixed value resistors R1 and R2 are connected to the power supply in one way, the power consumed by R1 is 9 watts; if the two resistors are connected to the power supply in another way, the power consumed by R1 is 16 watts, and the current passing through R2 is 4a. What are the power supply voltage and the resistance values of R1 and R2
- 8. 2:1 / 4, 0.24:56, 0.2:1 / 5, 125:1 / 4
- 9. In the experiment of measuring resistance by voltammetry, sliding rheostat has () A. Change the current in the circuit B. change the voltage at both ends of the measured resistance C. change the resistance value of the measured resistance D. protect the circuit
- 10. 3 / 8-5 / 6 =? It should not be divided into 9 / 24 to 20 / 24. If it is not enough, what should we do
- 11. This is the complete title: During the movement of slide P of rheostat R0, the indication range of voltmeter is 0-4V, and the indication range of ammeter is 0.5-1A. Calculate the organization of resistor R, the maximum resistance of rheostat R0 and the power supply voltage U
- 12. First column, second column, third column, fourth column First line 1 2 9 10 second line 4 3 8 11 third line 5 6 7 12 fourth line 16 15 14 13
- 13. The wrong understanding of Ohm's law is () A. For a certain section of conductor, the current in the conductor is directly proportional to the voltage at both ends. B. under certain voltage conditions, the current in the conductor is inversely proportional to the resistance of the conductor. C. The current in the conductor is determined by the voltage and resistance at both ends. D. the current in the conductor is independent of the voltage and resistance at both ends
- 14. The known elements are integer sequence {1}, {2,3}, {4,5,6}, {7,8,9,10} Starting from the second sequence, each number set has one more number than the previous number set, and the minimum number of each number set is 1 larger than the maximum number of the previous number set. Find the sum SN of all numbers in the nth number set
- 15. Given that the average of data a, B and C is D and the variance is e, what is the average and variance of a group of new data 3a-2, 3b-2 and 3c-2?
- 16. If the average of a group of sample data 2, 3, 7, 8, a is 5, then the variance S2 of the group of data is 0=______ ．
- 17. Among the 10 known data, the average and variance of the first nine data are 1 and 7, respectively The 10th data is equal to 11, so what is the variance of the 10th data?
- 18. The variance of sample data 10 10.19.7 9.9 10.3 is the mean of data 1-20-11, is the variance s #; yes
- 19. If the average of a set of data 2, 4, x, 6, 8 is 6, then the standard deviation of this set of data is () A. 10B. 8C. 6D. 22
- 20. If the average of sample data 3, 6, a, 4 and 2 is 5, then the variance of this sample is () A. 8B. 5C. 22D. 3