![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
Let the tolerance of the arithmetic sequence an be - 6, and a1 + A4 + A7... + A97 = 50, find the value of A3 + A6 + A9 +... + A99 Come on,
a1-a3=a4-a6=...=a97-a99=-2d=12
a3+a6+a9+..+a99=50-12*33=-346
Let {an} be an arithmetic sequence with a tolerance of - 2 if a1 + A4 + A7 + +A97 = 50, then A3 + A6 + A9 + +A99 equals ()
A. 82B. -82C. 132D. -132
Because {an} is an arithmetic sequence with tolerance of - 2, A3 + A6 + A9 + + A99 = (a1 + 2D) + (A4 + 2D) + (A7 + 2D) + +(A97 + 2D) = a1 + A4 + A7 + + A97 + 33 × 2D = 50-132 = - 82
It is known that {an} is an arithmetic sequence with tolerance of - 2. If A3 + A6 + A9 +.. + A99 = - 82, then a1 + A4 + A7 +.. A97 =?
a3+a6+a9+… +a99
=(a1+2d)+(a4+2d)+(a7+2d)+… +(a97+2d)
= a1+a4+a7+… +a97+(99/3)*2d
= a1+a4+a7+… +a97+66d
=-82
a1+a4+a7+… +a97=-82-66d=-82-66*(-2)=50
RELATED INFORMATIONS
- 1. Let {an} be an arithmetic sequence with a tolerance of - 2 if a1 + A4 + A7 + +A97 = 50, then A3 + A6 + A9 + +A99 equals () A. 82B. -82C. 132D. -132
- 2. Let {an} be an arithmetic sequence with a tolerance of - 2 if a1 + A4 + A7 + +A97 = 50, then A3 + A6 + A9 + +A99 equals () A. 82B. -82C. 132D. -132
- 3. Given that the sum of the first n terms of the arithmetic sequence {an} is Sn, and S10 = 12, S20 = 17, then S30 is () A. 20B. 15C. 25D. 30
- 4. The summation formula of arithmetic sequence is known in arithmetic sequence {an}, A5 = 6, a8 = 15, A14?
- 5. Arithmetic sequence: a1 + A5 + A9 = 2 π, is the value of COS (A2 + A8) -?
- 6. It is known that {an} is an arithmetic sequence. If a1 + A5 + A9 = 8 π, then the value of COS (A2 + A8) is______ ．
- 7. In the arithmetic sequence {an}, if S4 = 1, S8 = 4, then the value of A17 + A18 + A19 + A20 is () A. 9B. 12C. 16D. 17
- 8. Given the arithmetic sequence {an}, and A2 + a3 + A10 + a11 = 48, then A5 + A8=
- 9. Given the arithmetic sequence {an}, A6 = 5, A3 + A8 = 5, find A9 There is another problem: given the sequence of equal ratio numbers {an}, A6 = 192, a8 = 768, finding S10 requires calculation steps
- 10. In the arithmetic sequence {an}, A6 + A7 + A8 = 75, then A3 + a11 = () A. 48B. 49C. 50D. 51
- 11. It is known that the tolerance of the arithmetic sequence {an} is greater than 0, and A3 and A5 are two of the equations X & sup2; - 14x + 45 = 0. The sum of the first n terms of the sequence {BN} is Sn = 1-1 / 2B (1) Finding the general term formula of sequence {an}, {BN}; (2) Let CN = anbn prove CN + 1 ≤ cn
- 12. If the tolerance D of the arithmetic sequence (an) is not equal to 0, and A1 and A2 are two of the equations X & # 178; - a3x + A4 = 0 about X, then the general term formula of (an) is
- 13. If the tolerance of arithmetic sequence D ≠ 0, and A1, A2 are two of the equations X & # 178; - a3x + A4 = 0 about X, then the general term formula an of {an}= According to Weida's theorem, there is a1 + A2 = A3, A1A2 = A4, so how does a1 + A1 + D = a1 + 2D calculate?
- 14. It is known that no matter what the value of X is, there is a value of (a + 2b) x + (a-2b) = 3x + 5
- 15. Given that x = 10, y = 3A square-2b, and 2x-3y + 5 = 0, when a = (- 0.5), find the value of B and y I'll get higher marks
- 16. If x (upper right 3M + n-2) - 2Y (upper right m + N-1 of Y) = 6 is a bivariate linear equation about X and y, find the value of M and n
- 17. If x3m-2n-2yn-m-13 = 0 is a quadratic equation of two variables, then M=______ ，n=______ ．
- 18. Given the function f (x) = ACOS (Wx + a) as shown in the figure, if f (90 °) = (- radical 3) / 2, then f (0)= key (2) / root Take a look
- 19. The known function f (x) = ACOS ^ 2 (Wx + φ) + 1 (a > 0, w > 0,0)
- 20. It is known that the function f (x) = ACOS (Wx + φ) (a > 0, w > 0, - π / 2 ≤ φ ≤ π / 2) defined on R, and the difference between the maximum and the minimum is 4 The distance between the two lowest points is π, and all the symmetry centers of the function y = sin (2x + π / 3) image are on the symmetry axis of the image y = f (x) (1) The expression of finding f (x) (2) If f (X. / 2) = 3 / 2 (x ∈ [- π / 2, π / 2], find the value of COS (X. - π / 3) (3) Let vector a = (f (x - π / 6), 1), vector b = (1, cosx), X ∈ (0. π / 2), if vector a * vector B + 3 ≥. Constant holds, find the value range of real number M