Given that the quadratic function y = ax ^ 2 + BX + C (a is greater than 0) satisfies f (2-x) = f (2 + x), compare the sizes of F (1), f (2), f (4)

Given that the quadratic function y = ax ^ 2 + BX + C (a is greater than 0) satisfies f (2-x) = f (2 + x), compare the sizes of F (1), f (2), f (4)

From F (2-x) = f (2 + x), we can get that f (x) image is symmetric with respect to x = 2; f (1) = f (3)
And because a > O, f (x) increases monotonically on (2, infinity)
So f (2)

The quadratic function f (x) satisfies that f (x + 1) - f (x) = 2x, and f (0) = 1. (1) find the analytic expression of F (x); 2) on the interval [- 1,1],
The quadratic function f (x) satisfies f (x + 1) - f (x) = 2x and f (0) = 1
(1) Find the analytic expression of F (x);
(2) In the interval [- 1,1], the image of y = f (x) is always above the image of y = 2x + M. try to determine the range of real number M
The first problem is f (x) = x ^ 2-x + 1
The answer to question (2) is:
From the meaning of the title, it is found that x 2 - x + 1 ＞ 2x + m is constant on [- 1,1]
That is to say, X 2-3x + 1-m > 0 is constant on [- 1,1]
Let g (x) = x2-3x + 1-m, the symmetry axis of the image is a straight line,
So g (x) decreases on [- 1,1]
So only G (1) > 0, that is 12-3 × 1 + 1-m > 0,
The solution is m ＜ - 1
My problem is the second problem. I went to find the tangent line between y = 2x + m and f (x) = x ^ 2-x + 1, and worked out M = - 5 / 4, then I got M

The answer you get is in the interval [- ∞, + ∞]. The question requires that as long as you get the value range of m in the interval [- 1,1], the value range you get will be smaller than the correct interval

(1) The parabola y = x ^ 2 + 2x + 5 is transformed into y = a (x + m) ^ 2 + K (2), and the quadratic function y = 4x ^ 2 + 8x is transformed into y = a (x + m) ^ 2 + K (2) by collocation method

(1)y=x^2+2x+5
=x^2+2x+1+4
=(x+1)^2+4
(2)y=4x^2+8x
=4(x^2+2x)
=4(x^2+2x+1)-4
=4(x+1)^2-4

There is an ammeter with an internal resistance of 100 ohm and a partial full current of 500 μ A. if it is used to install an ammeter with a measuring range of 2.5A, it needs to be connected with a ohm
There is an ammeter with an internal resistance of 100 ohm and a partial full current of 500 μ A. if it is used to install an ammeter with a measuring range of 2.5A, a () ohm resistor is required

There is an ammeter with an internal resistance of 100 ohm and a partial full current of 500 μ A. if it is used to install an ammeter with a measuring range of 2.5A, a (0.02) ohm resistor is required

A calculation problem of real number
(4 times radical 5) / (- 5 radical 9 / 5)=

-4

What is the process of transforming electric energy into other forms of energy

The process of converting electric energy into other forms of energy is the process of electric energy doing work. For example, electric motors convert electric energy into mechanical energy, and household electric cookers and induction cooker convert electric energy into heat energy

Composition 800 words

In the middle of life, there are happiness, distress, confusion and sadness. Too many emotions are harmonious together. The short junior high school life becomes simple and complex, which makes people worry and aftertaste. Going to junior high school means that they have grown up, and they are not the "little princess" and "little master" that people love and protect

If angle 1 + angle 2 equals 90 °, angle 2 + angle 3 = 90 °, then angle 1 = angle 3, according to

Angle 1 + angle 2 = 90 push out angle 2 = 90 replace angle 1
Angle 2 + angle 3 = 90
Then: 90-angle1 + angle3 = 90
Angle 3 = 90-90 + angle 1
Angle 3 = angle 1

Known - 1 ＜ x ＜ 3 reduction √ X & # 178; - 6x + 9 + | x + 1|

Solution
-1

In the circuit shown in the figure, the resistance R1 = 4 Ω, R2 = 2 Ω, and the power supply voltage remains unchanged. When the switches S1 and S3 are open and S2 is closed, the indication of the ammeter is 0.5A; when the switches S1 and S3 are closed and S2 is open, the indication of the ammeter is 0.5A______ A．

When switches S1 and S3 are open and S2 is closed, R1 and R2 are connected in series. According to Ohm's law, the power supply voltage U = I (R1 + R2) = 0.5A × (4 Ω + 2 Ω) = 3V; when switches S1 and S3 are closed and S2 is open, R1 and R2 are connected in parallel. The total resistance R in the circuit is r1r2r1 + R2 = 4 Ω × 2 Ω 4 Ω + 2 Ω = 43 Ω. According to Ohm's law, I total = ur and = 3v43 Ω = 2.25A. Therefore, the answer is 2.25