Current location - Training Enrollment Network - Mathematics courses - High school mathematics ii
High school mathematics ii
Send three questions first and I'll send you the rest. I'm afraid I have to type them out one by one.

It's not good to be beaten by others if it's late.

1.a3+a7-a 10=8,a 1 1-a4=4

a3=a 1+2d a7=a 1+6d ……

a 1-d=8 7d=4 a 1=60/7

s 13 = 13a 1+ 13 * 12 * d/2 = 156

2 . a4a 6+2a5a 7+a6a 8 = 36 = a5^2+2a5a7+a7^2=36

(a5+a7)^2 =36

a5+a7=6

3. When n = 12345, |an|=an n= 6 7 8 9 10 |an|=-an.

a 1-a6 =-5d = a2-a7 =……= a5-a 10

S 10= -25d =50

4. The process of nkai11power-1 is a1(1+q)1= a12a/kloc-0.

5. because of d

When Sn takes the maximum value, n=5 or 6.