Let x obey the exponential distribution with parameter 2, then d (3x) = 36
D(3X)=9*D(X)=9*4=36
RELATED INFORMATIONS
- 1. There are () rational numbers x that make (x ^ 2 + 3x) ^ 2-2 (x ^ 2 + 3x) - 8 equal to zero A.2 B.3 C.4 D.5
- 2. Using the matrix method, the equations are: 2x1-3x2 + x3-x4 = 33x1 + x2 + X3 + X4 = 0 4x1 - X2 - x3-x4 = 7 - 2x1-x3 + X3 + X4 = - 5
- 3. How many times is polynomial-1 / 8x ^ 3-A ^ 2x ^ 2 + X? Is - A ^ 2 a coefficient or an unknown? How many times is 2 / 5x-by ^ 2?
- 4. Known x2-3x-1 = find the value of X4 + 1 / x4, x + 1 / X (correct title)
- 5. (3) It is known that X / (x 2 + x 2 + 1) = 1 / 4, x 2 / (x 4 + x 2 + 1)
- 6. If the coefficient of the quadratic term and the constant term of a quadratic trinomial with respect to the letter X are both 1 and the coefficient of the primary term is three fourths, then
- 7. The urgent need of College Mathematics: try to prove the reducibility of primitive polynomial x ^ 10 + x ^ 5 + 1 I just applied for the number, I hope you can help me
- 8. Let f (x), G (x) and H (x) be polynomials, and the first coefficient of H (x) is 1. It is proved that: (f (x) H (x), G (x) H (x)) = (f (x), G (x)) H (x)
- 9. A quadratic trinomial about the letter X, the coefficient of the quadratic term is - 1 / 3, the coefficient of the primary term is 1. The constant term is - 2 / 3, and the quadratic trinomial is?
- 10. If the coefficient of the quadratic trinomial of X is - 5, write this polynomial
- 11. (x + 1) (x + 2) (x + 3); (x + 19) (x + 20) expansion of the coefficient of the 18th power of X! Super
- 12. In the arithmetic sequence {an}, if A4 + A8 = 16, then A2 + a10=______ .
- 13. Let a ≠ 0 and f (x) = a (x ^ + 1) - (2x + 1 / a) have the minimum value - 1, let the first n terms of an and Sn = f (n), let BN = (A2 + A4 +...) +a2n)/n,
- 14. The sum of the first n terms of sequence an is SN. For N, it belongs to positive integer, and (n, Sn) is on the function f (x) = 2x ^ 2-x, Let CN = 2 / Anan + 1, tn be the sum of the first n terms of a sequence, and let tn be
- 15. The sum of the first n terms of the arithmetic sequence {an} is Sn = 4n2-25n
- 16. If A1 and A2 are known to be equal difference sequence and A1 = 10, their arithmetic mean is 53.5, then A13 is equal to I figured out 46, but every option was 46 a1 a2 a3 …… A30 is the arithmetic mean of arithmetic difference sequence
- 17. The tolerance of arithmetic sequence an is 1, a1 + A2 + a3 + +A99 = 99, then A3 + A6 + A9 +A96 + A99 =? The answer is 66, RT
- 18. It is known that the tolerance of {an} is 1, and a1 + A2 + +A98 + A99 = 99, then A3 + A6 + A9 + +a96+a99=? 55. I still don't understand.
- 19. When n is a natural number, 1, 2, 3, 4 2n denotes______ Number, 2N-1______ Count
- 20. If the first three terms of the arithmetic sequence an are A-1, a + 1 and 2a-3 respectively, then the general term formula of this sequence is?