Grade 7 Optimized Learning Mathematics P20 Final Question

There are 2003 terms in the original formula, and each term is: root number (1+1 k 2+1 (k+1) 2), k = 1, 2, 3, 4 ,..2003。

where 2 is squared.

First calculate the inside of the root number, the general fraction, the denominator: k 2*(k+1) 2, so you can go to the outside of the root number.

Molecule: k 2*(k+1) 2+k 2+(k+1) 2=k 2*(k+1) 2+2k 2+2k+1=k 2*(k+1) 2+2k*(k+1)+1=[k*(k+1)+1] 2, so you can also go outside the root number.

So, each term becomes: [k*(k+1)+1] k*(k+1)=1+1 [k*(k+1)]=1+1 k-1 (k+1).

From item 1 to item 2003, we get: 1*2003+1 1-1 2004=2004-1 2004.

Let pf1: y=k1(x+1) and pf2=k2(x-1).

Simultaneous equations with ellipses, respectively.

1+2k1 )x +4k1 x+2k1 -2=0, (so let a(x1,y1),b(x2,y2)).

x1+x2=-4k1²/(1+2k1²)①x1x2=(2k1²-2)/(1+2k1²)②

In the same way, let c(x3,y3) and d(x4,y4).

1+2k2²)x²-4k2²x+2k2²-2=0

x3+x4=4k2²/(1+2k2²)③x3x4=(2k2²-2)/(1+2k2²)④

According to koa+kob+koc+kod=0

y1/x1+y2/x2+y3/x3+y4/x4=0

According to y=k1(x+1) y1=k1(x1+1), y2

According to y=k2(x-1), y3=k2(x3-1), y4

Substitution to simplify.

k1(2x1x2+x1+x2)/(x1x2)+k2[2x3x4-(x3+x4)]/x3x4=0

by 2k1 (k1 -1)-2k2 (k2 -1)=0

Let p(n,2-n) k1=(2-n-0) (n+1)=(2-n) (n+1), k2=(2-n) (n-1).

Generation k1 k2+k1k2 =k1+k2

k1k2(k2+k1)=k1+k2

k1k2=1 or k1k2=0 or (k1+k2)=0

are all true. n=5, 4, n=2, n=0.

p(5/4,3/4),p(2,0),p(0,2)

Please type the title up, there is no book.

If a(x1,y1) b(x2,y2).

Then the coordinates of the hail hitting the excittion, i.e., the source socks are ((x1+x2) 2, (y1+y2) 2).

In the sixth column, there are 2 taels of Chong Sun selling and teasing.

The 2 of the third line is wrong, which answer Kai:

The 2 in the first line is wrong, the answer:

c=180-∠b-∠a=

a<= c<= voltsy b

a<=out of luck key a<=

The solution is 30<=a<=40°

75<= b<=100

I don't know how to bored and didn't ask again

There are 16 numbers here, which are calculated as 1+2+3+. 16=（1+16）+（2+15）+。8+9）=17*8=136；

4 numbers per row, then the value of each row is 136 4 = 34, then the sum of the diagonal lines of each row and column is also 34, fill in the first line, and so on, and obtain.