Let A 1 2X3 4X5 6X7 8 X99 100 and compare the size of A with 1 10 5

a=1/2x3/4x5/6x7/8...x99 100 assumes a number b

b=2/3x4/5x6/7x8/9...x98 99 then axb = 1 100

And 1 100 = 1 10x1 10

Because b a, then b 1 10

then a 1 10

Answer: a 1 10.

Our teacher talked about it).

a=1/2*3/4*5/6*..99 100 Construct another one:

b=2/3*4/5*6/7*..100/101a*b=1/2*2/3*3/4*4/5*..99/100*100/101=1/101

Cause 1 2 < 2 3; 3/4 < 4/5; 5/6 < 6/7...99/100 < 100/101

So aa*a < a*b

and a*b =1 101 < 1 100

So a*a < 1 10*1 10

So a < 1 10

ln(1)-[ln(2)+ln(3)]-ln(4)+ln(5)]-ln(6)+ln(7)]-ln(100) and ln(1)-ln(100)!

One more change: ln(1)-ln(2)-ln(3)-ln(4)-ln(5)-ln(6)-ln(7)-...ln(100)

You can see which one is bigger!

This question can become:

The size between LG(1)-[LG(2)+LG(3)]-LG(4)+LG(5)]-LG(6)+LG(7)]-LG(100) and LG(1)-LG(100)!

One more change: LG(1)-LG(2)-LG(3)-LG(4)-LG(5)-LG(6)-LG(7)-...lg(100)

lg(1)-lg(100)=-

So the original < 1 10=lg(-10).

We can simplify the formula of n to get the square of a minus 4a plus 1, so m n

Used as a difference method, you can compare the size of the two and judge which is bigger and which is smaller faster.

(5x²﹢30xy﹢51y²)/(x²﹢6xy﹢11y²)=(5x²﹢30xy﹢55y²-4y²)/(x²﹢6xy﹢11y²)=[5(x²+6xy+11y²)-4y²]/(x²+6xy+11y²)

5-4y²/[(x+3y)²+2y²]

x+3y) 0,5-4y [(x+3y) +2y] 5- 4y (0+2y)=5-2=3 When x=-3y, take the equal sign.

The minimum value of 5x 30xy 51y ) (x 6xy 11y) is 3. This question tests basic inequalities You should pay attention to the correctness of the formula and don't make mistakes.

Compare the size of the following equations 4 +3 2 4 3,(-2) +1 2 (-2) 1,(root number 2) + root number 1/2), (1 divided by root number 2) 2 root number 2 root number 2/2, (root number 3) + root number 3) 2 root number 3 root number 3 Through observation and induction, write a general conclusion that reflects this law a2+b2 2ab

Hello classmates, if the problem has been solved, remember the upper right corner Oh Yours is my affirmation Thank you.

3 2*3 3,4 -2*4 8 [(n+2) -2(n+2)] =(n+2) n ,n>=1

4,6,8,10 into equal differences, [4+(n-1)*2] =(2n+2) The series of numbers 5, 10, 17, and 26 is more complicated to solve, so I don't solve it.

an＝5+（n+3)(n-1)

a n=[5+(n+3)(n-1)] =(n +2n+2) rule: [(n+2) -2(n+2)] 4+(n-1)*2] =[5+(n+3)(n-1)].

i.e. (n+2) n +(2n+2) = (n +2n+2).

m-n=10a Stove +2b -7a+6-(a +2b hidden good knowledge +5a +1).

9a²-12a+5

9(a-2/3)²+1

then m > sock liquid n