In the arithmetic sequence {an} and proportional sequence {BN} with non-zero tolerance, we know that A1 = B1 = 1, A2 = B2, a8 = B3; (1) find the tolerance D of {an} and the common ratio Q of {BN}; (2) let CN = an + BN + 2, find the general term formula CN and the first n term and Sn of {CN}

In the arithmetic sequence {an} and proportional sequence {BN} with non-zero tolerance, we know that A1 = B1 = 1, A2 = B2, a8 = B3; (1) find the tolerance D of {an} and the common ratio Q of {BN}; (2) let CN = an + BN + 2, find the general term formula CN and the first n term and Sn of {CN}

(1) From A2 = b2a8 = b3a1 = B1 = 1, we get 1 + D = Q1 + 7d = Q2 (3 points) ∧ (1 + D) 2 = 1 + 7d, that is, D2 = 5D, and ∫ D ≠ 0, ∧ d = 5, so q = 6 (6 points) (2) ∫ an = a1 + (n-1) d = 5n-4, BN = b1qn-1 = 6n-1 ∧ CN = an + BN = 5n-4 + 6n-1 + 2 = 6n-1 + 5n-2 (9 points), so Sn = 1-6n1 -
It is known that the sequence {an} is an arithmetic sequence with non-zero tolerance, A1 = 2, and A2, A4 and A8 are equal proportion sequence. (1) find the general term formula of the sequence {an} & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; (2) find the sum of the first n terms of the sequence {3an}
(1) ∵ sequence {an} is an arithmetic sequence with non-zero tolerance, A1 = 2, and A2, A4, a8 are equal ratio sequence, with ∵ 2 + 3D) 2 = (2 + D) (2 + 7D), the solution is d = 2, ∵ an = 2n. (2) ∵ an = 2n, ∵ 3an = 32n = 9N, the first term of this sequence is 9, and the common ratio is 9. From the sum formula of equal ratio sequence, the first n term of {3an} and Sn = 9 (1-9n) 1-9 = 98 (9n-1) are obtained
In the arithmetic sequence {an}, if the tolerance D ≠ 0 and A2, A3 and A6 are in the same ratio sequence, then the common ratio q is equal to ()
A. 1B. 2C. 3D. 4
Because A2, A3 and A6 are equal ratio sequence, so A32 = A2 · A6 {(a1 + 2D) 2 = (a1 + D) (a1 + 5d)} 2a1d + D2 = 0. ∵ D ≠ 0, ∵ d = - 2A1. ∵ q = a3a2 = a1 + 2da1 + D = 3. So choose C
In the arithmetic sequence {an}, the tolerance D ≠ 0, A2 is the median of the ratio of A1 and A4, the known sequence A1, A3, AK1, ak2 ，akn，… The general term kN of the sequence {kn} can be obtained
According to the meaning of the question, A22 = a1a4, i.e. (a1 + D) 2 = A1 (a1 + 3D) and D ≠ 0, A1 = D and A1, A3, AK1, ak2, AKN, form an equal ratio sequence, and the common ratio of the sequence is q = a3a1 = 3dd = 3, so AKN = A1 · 3N + 1 and AKN = a1 + (KN − 1) d = KNA1  kn = 3N + 1, so the general term of the sequence {kn} is kn = 3N + 1
What is the principle of an addition formula composed of 0123456789
OA1 = 1 S1 = 1 / 2 oa2 = √ 2 S2 = √ 2 / 2 oa3 = √ 3 S3 √ 3 / 2 find the value of oa10
This is the second Pythagorean theorem,
0A1²=1²
OA2²=1²+1²
OA3²=1²+1²+1²
.
∴OA10²=10
Ψ oa10 = root 10
The area is the product of two right angle sides divided by 2
How to add a positive number to a negative number
A positive number plus a negative number equals the absolute value of the positive number minus the negative number
For example, + 3 plus - 2, because the absolute value of - 2 is 2, the result is 3 minus 2, that is (+ 3) + (- 2) = 3-2 = 1
Positive plus negative equals positive minus positive
How to list the vertical form of decimal point multiplication
As usual, the column is just a decimal point
Use 0123456789 to form an addition formula, each number is used only once, 334 format
There are 96 formulas: 246 + 789 = 1035249 + 786 = 1035264 + 789 = 1053269 + 784 = 1053284 + 769 = 1053 286 + 749 = 1035289 + 746 = 1035289 + 764 = 1053324 + 765 = 1089325 + 764 = 1089 342 + 756 = 1098346 + 752 = 1098347 + 859 = 1206349 + 857 = 1206352 + 746 = 1098 356 + 742 = 1098357 + 849 = 1206359 + 847 = 1206364 + 725 = 1089365 + 724 = 1089 423 + 675 = 1098425 + 673 = 1098426 + 879 = 1305429 + 876 = 1305, 432+657=1089 437+589=1026,437+652=1089,439+587=1026,452+637=1089,457+632=1089 473+589=1062,473+625=1098,475+623=1098,476+829=1305,479+583=1062 479+826=1305,483+579=1062,487+539=1026,489+537=1026,489+573=1062 537+489=1026,539+487=1026,573+489=1062,579+483=1062,583+479=1062 587+439=1026,589+437=1026,589+473=1062,623+475=1098, 624+879=1503 625+473=1098,629+874=1503,632+457=1089,637+452=1089,652+437=1089 657+432=1089,673+425=1098,674+829=1503,675+423=1098,679+824=1503 724+365=1089,725+364=1089,742+356=1098,743+859=1602,746+289=1035 746+352=1098,749+286=1035,749+853=1602,752+346=1098,753+849=1602 756+342=1098,759+843=1602,764+289=1053,764+325=1089, 765 + 324 = 1089, 769 + 284 = 1053784 + 269 = 1053786 + 249 = 1035789 + 246 = 1035789 + 264 = 1053, 824 + 679 = 1503826 + 479 = 1305829 + 476 = 1305829 + 674 = 1503843 + 759 = 1602, 847 + 359 = 1206849 + 357 = 1206849 + 753 = 1602853 + 749 = 1602853 + 749 = 1206, 859 + 347 = 1206859 + 743 = 1602874 + 629 = 1503876 + 429 = 1305879 + 426 = 1305, 879 + 624 = 1503, please refer to it!
S1:S2=2:5 S2:S3=4:10 S1:S2:S3=
Let S1 = 2x, then S2 = 5x
S2:S3=4:10=2:5
S3=(5S2)/2=25x/2
S1:S2:S3=2x:5x:25x/2
=4:10:25