2000loge( 1+M/N)= 12

500/3loge( 1+M/N)= 1

loge( 1+m/n)^500/3=loge·e

( 1+M/N)^500/3=e

1+M/N=e^3/500

M/N=e^3/500- 1

Answer: It is 3/500- 1 time, reaching 12 km/s ... (you can use it instead of inspection).

12, (1) when O=2700, v =1/2log32700/100 =1/2log327 = 3/2 (m/s).

(2) When v =, 1/2 log 3 O/ 100 = 0,

So log3 O/ 100= zero, so o/100 =1o =100.

(0 stands for the letter "o" and zero stands for the number "0")

4.( 1)f(x)+g(x)= loga(x+ 1)+loga( 1-x)。 To make this function meaningful, simply

X+ 1 > 0, 1-x > 0 gives-1 < x < 1, so the domain of the function f(x)+g(x) is {x |-1< x < 650.

(2) let f(x)+g(x)=M(x), then m (x) = loga (x+1)+loga (1-x),

M(-x)= loga(-x+ 1)+loga( 1+x)= loga(x+ 1)+loga( 1-x)= M(x)，

So M(x) is an even function, that is, f(x)+g(x) is an even function.

55555 ... you want a topic. I have been writing for a long time.

9. Without considering the air resistance, the maximum velocity v(m/s) of the rocket and the mass M kg of the fuel,

The functional relationship of rocket mass (except fuel) is v=2000ln( 1+M/N). When the fuel mass is several times that of a rocket, the maximum speed of the rocket can reach 12km/s?

12, Atlantic salmon spawn against the current every year. Scientists who study salmon have found that the swimming speed of salmon can be expressed as a function v= 1/2log3 o/ 100, and the unit is m/s, where o represents the number of units of oxygen consumption of fish.

(1) When the oxygen consumption of a fish is 2700 units, what is its swimming speed?

(2) Calculate the number of units of oxygen consumption when a fish is still.

4. The functions f (x) = loga (x+ 1) and g (x) = loga (1-x) (A > 0 and a≠ 1) are known.

(1) Find the domain of function f(x)+g(x)

(2) Judge the parity of the function f(x)+g(x) and explain the reasons.