1. The function y = ax ^ 2 + BX + C (a is not equal to 0) is a necessary and sufficient condition for an image to cross the origin_ 2. Known proposition p: "inverse ax belongs to R, inverse EM belongs to R, so that 4 ^ X-2 1. The function y = ax ^ 2 + BX + C (a is not equal to 0) is a necessary and sufficient condition for an image to cross the origin 2. Given proposition p: "inverted ax belongs to R, inverted EM belongs to R, so that 4 ^ X-2 ^ (x + 1) + M = 0", if proposition p is a false proposition, then the value range of real number m is

1. The function y = ax ^ 2 + BX + C (a is not equal to 0) is a necessary and sufficient condition for an image to pass through the origin
2. Proposition p is a false proposition, which means that for all m, 4 ^ X-2 ^ (x + 1) + M = 0 does not hold, (2 ^ x) ^ 2-2 * 2 ^ x + M = 0, and the axis of symmetry is 2 ^ x = 1, that is, x = 0,1-2 + m > 0
The range of M is m > 1

It is known that the image of quadratic function y = ax ^ 2 + BX + C (a is not equal to 0) passes through points a (- 2, - 1) and B (6,3), and the opening is upward and intersects with y axis at point C. if the area of triangle ABC is 12, the analytic expression of quadratic function is obtained

By substituting a and B coordinates into the analytic expression of quadratic function, it is obtained that:
-1=4a-2b+c……………… （1）
3=36a+6b+c……………… （2）
When x = 0, y = C
According to the meaning of the title, a > 0, C < 0
Let the analytic expression of the line where AB is located be y = MX + n
Substituting a and B coordinates, we get the following result:
-1=-2m+n
3=6m+n
The solution is as follows
m=0.5
n=0
The analytical formula is y = 0.5x
When x = 0, y = 0
The area of ABC is:
1/2*(-c)*2+1/2*(-c)*6=12
c=-3
Substituting (1) and (2), we get:
-1=4a-2b-3
3=36a+6b-3
The solution is as follows
a=1/4
b=-1/2
The analytic formula of quadratic function is as follows:
y=1/4x^2-1/2x-3

We know that the image of function f (x) = loga1 − mxx − 1 (a > 0, a ≠ 1) is symmetric about the origin. (1) find the value of M; (2) judge the monotonicity of function f (x) on (1, + ∞), and prove it according to the definition

(1) The image of ∵ function f (x) = loga1 − mxx − 1 (a > 0, a ≠ 1) is symmetric about the origin ∵ function is odd and satisfies f (- x) + F (x) = 0, that is, loga1 + MX − x − 1 + loga1 − mxx − 1 = 0 holds for any X in the domain of definition, that is, loga (1 + MX − x − 1 · 1 − mxx − 1) = loga1, 1 − mxx21 − x2 = 1 holds for any X in the domain of definition, ∵ M2 = 1, M = ± 1 is obtained, and m = 1 does not meet the meaning of the test (2) when 0 < a < 1, f (x) is an increasing function of (1, + ∞); when a > 1, f (x) is a decreasing function of (1, + ∞). It is proved that from (1), f (x) = loga1 + XX − 1, (x > 1) let t = 1 + X & nbsp; X & nbsp; Let 1 ＜ x1 ＜ X2, then T1 = 1 + x1x1 − 1, T2 = 1 + x2x2 − 1, we can get T1-T2 = 1 + x1x1 − 1-1 + x2x2 − 1 = 2 (x2 − x1) (x1 − 1) (x2 − 1) ＞ 0, there is T1 ＞ T2, t = 1 + X & nbsp; X − 1 is the decreasing function on (1, + ∞). According to the monotonicity rule of composite function, it is obtained that when 0 < a < 1, f (x) is the increasing function of (1, + ∞); when a > 1, f (x) is the decreasing function of (1, + ∞)

If f (x) = x & # 178; - 2cosx + A has a unique zero, then a =?
If the function f (x) = x & # 178; - 2cosx + A has a unique zero point, then a = 2

f(x)=x²-2cosx+a
f'(x)=2x+2sinx
Further derivation
f''(x)=2+2cosx=2(1+cosx)≥0
F '(x) is an increasing function
that
∵f'(0)=0
When x > 0, f '(x) > 0, f (x) increases
x

How to calculate the power consumption of household appliances?
For example, if the power of a TV set is 300W, what is the power consumption per hour?
How to calculate according to the current 1 yuan per kilowatt hour?

One degree of electricity is 1000 W / hour
A kilowatt electric appliance consumes one degree of electricity when it works for one hour
The above is a written statement and a definition
The resulting unit of the formula kilowatt hour is the degree
To put it simply, a 100 watt electric appliance needs to work for 10 hours and consumes one degree of electricity!
300 W is 3 / 10 kwh per hour

Calculation: 1-3 + 5-7 + 9-11 + 13 - －39＋41

1 + 2 * 10 = 21, take every two of the last 40 items as a whole, it's very simple! To do this kind of problem, you should pay attention to the law of data analysis, and then do it. I believe you will become better in the future!

Can the electric vehicle with 60V battery and 800W motor overpressure 72V? Will it burn? What do you need to do? What do you need to change? What is the speed of this modified vehicle?

Do you mean to use the 72V battery when the overpressure reaches 72V? If the overpressure does not burn, the 72V battery will certainly burn. The 800W motor is generally brushless motor, and the speed of the brushless motor is so large, so the speed will not increase too much. If you want to improve the speed, you can use the AC chopper: such as Curtis 1230-2402 controller, It can easily pull more than 4T goods. It can also be refitted into an electric motorcycle with a speed of 80 per hour, but the cost and technical requirements are relatively high. There are not many people in China who are engineers

(0.8 * 19.85 * 0.125 + 0.075 * 0.125 / 0.625) * 100-37.5 * 4 calculated by a simple method

(0.8*19.85*0.125+0.075*0.125/0.625)*100-37.5*4
=(19.85*0.1+0.075/5)*100-150
198.5+1.5-150
=200-150
=50

What are all the formulas of physical power in the second grade of junior high school

Power refers to the work done by an object in unit time, that is, power is the physical quantity that represents the speed of work. The formula of power is power = work / time, and the formula of power is p = w / T = UI = I, R P represents power, the unit is "Watt" for short, and the symbol is "W". W represents work, and the unit is "Joule"

How to calculate 2.4 ÷ (0.7 + 0.14) 17.6-7.6 × 1.4-5.36

2.4÷（0.7+0.14）
＝2.4÷0.84
＝0.2÷0.07
＝20/7
17.6－7.6×1.4－5.36
＝17.6-10.64-5.36
＝17.6-（10.64+5.36）
＝17.6-16
＝1.6