If LGA + LGB = LG (2a + b), then the minimum value of AB is

If LGA + LGB = LG (2a + b), then the minimum value of AB is

lga+lgb=lg(2a+b),
lg(ab)=lg(2a+b)
ab=2a+b≧2√(2ab)
That is: ab ≥ 2 √ (2Ab)
a²b²≧8ab
Results: ab ≥ 8
If and only if 2A = B, the equal sign holds
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a>1 lga.lgb=4 The minimum value of LG (AB) is 1 LG2?

Because a > 1, so LGA > 0, again lga.lgb=4 So LGB > 0
Therefore, from the basic inequality
lg(ab)=lga+lgb>=2sqrt( lga.lgb )=2sqrt(lg2/4)=sqrt(lg2)

If a 25 watt bulb consumes one kilowatt hour in 40 hours, how many kilowatt hours can 25000000 25 Watt lamps save
Using science and Technology Law

Each bulb uses 40 hours less every month, saving 2.7 × 10 ^ 7 degree

It is known that f (x) = ax + B / 1 + x ^ 2 is an odd function defined on (- 1,1), and f (1 / 2) = 2 / 5
It is proved that f (x) is an increasing function in the domain of definition
(2) solve the inequality f (t-1) + F (T) < 0
I don't think it's right on the first floor, but I've got two questions. How do you know I had three questions?

F (x) = (AX + b) / (1 + x ^ 2), B = 0 can be obtained according to parity, and a = 1 can be obtained from the following conditions
Therefore, it is proved that f (x) = x / (1 + x ^ 2) is an increasing function in the domain of definition
Set - 1

A bulb marked with "220 V, 40 W" is connected to a circuit, and the measured current through it is 0.15 a, then the actual power of the bulb ()
A. Equal to 40wb. Equal to 33wc. Less than 33wd. None of the above is true

The resistance of the bulb is: r = u2p = (220V) 240W = 1210 Ω. When the current passing through it is 0.15A, the actual power of the bulb is: P '= (I') 2R = (0.15A) 2 × 1210 Ω = 27.225w < 33W

Simple calculation 4753-2993 0.625-3.75 + 0.375-6.25

Question 1 = 4753-3000 + 7
=1753+7
=1760
Question 2 = 0.625 + 0.375 - (3.75 + 6.25)
=1-10
=-9

When a DC motor works normally, the voltage at both ends is 240V and the current passing through it is 2.5A

96 ohm

Recursive equation calculation 0.78 + 8.4 △ 4.2 × 3.6

0.78+8.4÷4.2×3.6
=0.78+2x3.6
=0.78+7.2
=7.98

Dry battery discharge is to convert chemical energy into electrical energy, so what can dry battery charging convert and why

Electric energy is converted into chemical energy. Discharge is due to the transfer of electrons in the chemical reaction of chemical substances in the battery, which leads to the formation of electric current. Charging is to lead the current back to the chemical substances in the form of electrons, so that the chemical reaction opposite to discharge occurs, that is, reverse reaction. The electric energy is stored in the form of chemical energy

In connection with real life, write a practical problem about fractional equation 10 / x = 10 / 2x + 1 / 6, which requires complete expression, sufficient conditions, and write out the solution process

An engineering team's road construction was originally planned to be completed in X days, but for some reasons, the speed can only reach half of the original speed. In this way, the road completed after 10 days' work is less than 1 / 6 of the original plan, so the original plan can be completed in a few days
Multiply both sides by 2x to get 10 = 5 + 1 / 6x
1 / 6x = 5
The solution is x = 30
The test shows that x = 30 is in line with the meaning of the problem and is not an increasing root, so x = 30 is the solution of the equation