Image passing of function y = - 2x + 4___________ The area of the triangle formed by the quadrant and the two coordinate axes is___ I know the main process of the first two lectures

Image passing of function y = - 2x + 4___________ The area of the triangle formed by the quadrant and the two coordinate axes is___ I know the main process of the first two lectures

Image passing of function y = - 2x + 4__ 1 2_ 4________ The area of the triangle formed by the quadrant and the two coordinate axes is_ 4__
Please click the "select as satisfactory answer" button below,
The first, second and fourth quadrants are 4
1、 Two, four
Four
Proof: for any positive integer n, the inequality ln ((n + 2) / 2)
It is proved by mathematical induction that ln ((1 + 2) / 2) = ln (3 / 2) = 1) inequality holds when n = 1, that is, ln ((K + 2) / 2) = {[(K + 2) / (K + 1)] ^ (K + 1)} ^ [1 / (K + 1)] = (K + 2) / (K + 1) = 1 + 1 / (K + 1) > 1 + 1 / (K + 2)
=(k+3)/(k+2)
So when n = K + 1 (k > = 1), (K + 3) / 2
Suppose that the N + 1 inequality is established, and then you can exit the sub inequality as a condition
What are the commonly used formula and deformation formula of junior high school physics electric power?
We should focus on the deformation formula,
1. P = w / T can be changed to w = Pt, t = w / P
2. P = UI can be changed to u = P / I, I = P / u
R / u = P * u
4. P = I * I * r can be changed into I * I = P / R, r = P / I * I
(I * I is the square of I, u * u is the square of U)
P=UI=W/t=I^2R ~*^o^*
P = UI = u * U / r = I * I * r = w / T, where p = I * I * r is deformed according to the formula P = I * I * r / T, so it is only suitable for pure resistance circuit.
P=UI=I2R=U2/R
P=W/t
Calculation of the total power in the circuit; P = P1 + P2 + P3... + PN
1kW = 1000W, 1HP = 735w
P=UI=W/T
P = the square of U / R (P = UI, u = IR)
The square r of P = I (P = UI, I = u / R)
Ptotal = P1 + P2 + P3... + PN
I=U/R
U=IR
R=U/I
P=W/T
P=UI
P=U^/R
P=I^R
Q = uit physical quantity physical formula
Current definition I = q / T Ohm's law I = u / R series circuit I = I1 = I2 parallel circuit I = I1 + I2
Voltage series circuit u = U1 + U2 parallel circuit u = U1 = U2
Resistance series R total = R1 + R2 Parallel R total = R1... Expansion
I=U/R
U=IR
R=U/I
P=W/T
P=UI
P=U^/R
P=I^R
Q = uit physical quantity physical formula
Current definition I = q / T Ohm's law I = u / R series circuit I = I1 = I2 parallel circuit I = I1 + I2
Voltage series circuit u = U1 + U2 parallel circuit u = U1 = U2
Resistance series connection r total = R1 + R2 parallel connection r total = r1r2 / (R1 + R2)
Electric power definition P = w / T universal formula P = UI
Definition formula of electric work w = uitknown electric power W = Pt known electric quantity w = UQ
Joule's law of conductor heat q = i2rt
Area square s = A2 rectangle s = AB circle s = π (D / 2) 2
Volume cylinder v = sh drainage method v solid = v2-v1 cube v = A3 immersion V drainage = V matter
Velocity definition v = s / T average velocity v = s total / T total
Density definition formula ρ = m / V
Gravity g = mg
Buoyancy formula method f floating = ρ liquid GV row weighing method f floating = G-F 'floating and suspension f floating = g Archimedes principle f floating = g row
Cause f floating = f upward - f downward when sinking to the bottom f floating = G-N
Pressure definition formula P = f / s liquid interior P = ρ GH
Power (Mechanical) definition P = w / T vehicle power P = FV
Work (Mechanical) definition formula w = FS total work w total = w useful + W amount
Lever balance condition f1l1 = f2l2
Force in the same direction f = F1 + F2 opposite direction f = F1-F2 pressure of objects on the horizontal table f = g pressure of total liquid and gas f = PS
Definition formula of mechanical efficiency: η = w useful / W total lifting weight: η = GH / Fs horizontal moving weight: η = FS / Fs
Thermal fuel combustion q = QM body heat absorption and release q = cm Δ t
Mechanical energy mechanical energy = kinetic energy + potential energy
Q=U^/Rt
Q = I ^ RT
Eat more dishes
w=pt p=u2/R p=I2R
12. P = UI (empirical formula, suitable for any circuit)
13. P = w / T (definition, suitable for any circuit)
14. Q = I ^ 2rt (Joule's law for any circuit)
15．P=P1+P2+… +PN (suitable for any circuit)
16. W = uit (empirical formula, suitable for any circuit)
17. P = I ^ 2R (compound formula, only suitable for pure resistance circuit)
18. P = u ^ 2 / R
12. P = UI (empirical formula, suitable for any circuit)
13. P = w / T (definition, suitable for any circuit)
14. Q = I ^ 2rt (Joule's law for any circuit)
15．P=P1+P2+… +PN (suitable for any circuit)
16. W = uit (empirical formula, suitable for any circuit)
17. P = I ^ 2R (compound formula, only suitable for pure resistance circuit)
18. P = u ^ 2 / R (compound formula, only suitable for pure resistance circuit)
19. W = q (empirical formula, only suitable for pure resistance circuit. Where W is the work done by the current flowing through the conductor and Q is the heat generated by the current flowing through the conductor
20. W = I ^ 2rt (compound formula, only suitable for pure resistance circuit)
21. W = u ^ 2T / R (compound formula, only suitable for pure resistance circuit)
22. P1: P2 = U1: U2 = R1: R2 (the relationship between electric power and voltage and resistance in series circuit: in series circuit, the ratio of electric power is equal to the ratio of voltage and resistance)
23. P1: P2 = I1: I2 = R2: R1 (the relationship between electric power and current and resistance in parallel circuit: in parallel circuit, the ratio of electric power is equal to the ratio of their corresponding current and the inverse ratio of their corresponding resistance)
The area of the triangle formed by the image of the function y = 2x + m and y = - 2x + m and the X axis is 2
The intersection of y = 2x + m and y = - 2x + m is (0, m)
The intersections with X-axis are (- M / 2,0) and (M / 2,0) respectively
The length of triangle bottom is | M / 2 - (- M / 2) | = | m |;
The triangle area is s = | m | ^ 2 / 2 = 2;
m=±2
y=2x+m
The intersection of y = - 2x + m (0, m)
The intersection points with X axis are (- M / 2,0), (M / 2,0) respectively
Area of enclosed triangle: m ^ 2 / 2 = 2
m=±2
Prove inequality 1 / (n + 1)
Proof: prove it by the second mathematical induction. 1. When n = 1, the proposition is obviously tenable. That is: 1 / 2 < ln3-ln2 < 1 (1); suppose that all propositions are tenable when n ≤ K. that is, when n = 2, there are: 1 / 3 < ln3-ln2 < 1 / 2 (2);. Add the two sides of the first K-2 inequalities to get: 1 / 2 + 1 / 3 + 1 / 4 +. + 1 / (k-1) < ln (k-1)
How to use the two formulas of physical electric power and electric work?
P=U^2/R
P=I^2R
When to use each type, please give a brief explanation
In fact, it can be used in any situation (pure resistance circuit)
If it's convenient, the first one is for parallel connection
The second one is more convenient for series connection
I haven't heard of any difference
Just pay special attention to the corresponding relationship when using, otherwise it is easy to make mistakes
Of course, there is a difference... Below is the heating power, above is the total power. Only in the pure resistance circuit, the two can be used with each other. If there's a device in the circuit, such as an engine, that doesn't just turn electrical energy into heat, it's not the same
PT = I ^ 2rt and T P = I ^ 2R are eliminated on both sides. This is Joule's law. They have different meanings. It should be like this....
The length of an equilateral triangle is 4. If the length of an equilateral triangle is increased by X, the area will be increased by Y. find the functional relation of Y with respect to X
The answer should be pictures, don't copy other people's, don't /, √, these, otherwise you can't see which ones are the root sign and the score=
I'll take a picture
ln(n+1)>1/2+1/3+1/4+...1/n+1
Let f (x) = ln (1 + x) - [x / (1 + x)], X ∈ (0,1]
F '(x) = [1 / (1 + x)] - [1 / (1 + x) & # 178;] = x / (1 + x) & # 178; > 0, so f (x) increases in (0,1], and the function f (x) > F (0) = 0
Then ln (1 + x) > x / (1 + x), X ∈ (0,1]
Let x = 1 / N, then ln [1 + (1 / N)] > 1 / (n + 1), n ≥ 1, and N ∈ n*
In other words, LN [(n + 1) / N] > 1 / (n + 1), 〈 ln (n + 1) - lnn > 1 / (n + 1)
ln2-ln1+ln3-ln2+...+ln(n+1)-lnn>1/2 + 1/3 +...+1/(n+1)
It is proved that ln (n + 1) - ln 1 > 1 / 2 + 1 / 3 +. + 1 / (n + 1)
Using inequality
Ln (1 + 1 / x) > 1 / X
Add x from 1 to n
Physical electric power formula (including deformed)
More is better. Be specific
P = w / T = I ^ 2R = u ^ 2 / r = P total - P ~ = UI
It can also be calculated by the relationship between resistance and power, current and power, such as two parallel resistors P1 / P2 = R2 / R1, two series resistors P1 / P2 = R1 / R2
If it is not a pure resistance circuit, such as a coil, motor and other devices, it is generally calculated with P total - P, or with the external work / efficiency of the motor + the heat consumed by the resistance
p=uI
p=I^2Rt
p=u^2/R
p=w/t
P=UI=U^2/R=I^2R=W/t
P=W/t=UI=U2/R=I2R
If the area of an equilateral triangle is y and the side length is x, then the function of Y with respect to X is
The answer is y = root of 4, 3x square
The area of a triangle is divided by the base times the height by two
This triangle is also an equilateral triangle
So h = (√ 3) x / 2
y=(√3)x*x/2*1/2=(√3)x^2/4