Let a and B be nonzero vectors, if (a + b) · B = 2|b|2, and |b ||
(a + b) · B = 2 | B | ^ 2 = AB + B ^ 2 = 2 | a | B | cos θ + | B | ^ 2, then 2 | a | cos θ = | B |
Cos θ = | B | / (2 | a |) and | B ||
RELATED INFORMATIONS
- 1. If vectors a and B are two non-zero vectors, then the range of the angle between vectors a and B is A,(0,π) B,【0,π) C,(0,π】 D,
- 2. The fourth problem is that we know the first-order function s = 3T + 2
- 3. Given a function y = 2x-6 Q: when - 1 < x < 2, find the value range of Y
- 4. If y = - 0.5x + 3, then - 2
- 5. Given the increasing function of F (x) in the domain of definition [- 2,1], f (t-1) < f (1-3T) can find the range of T
- 6. If a and B satisfy 3 √ a + 5 | B | = 7, what is the value range of S = 2 √ A-3 | B |? In a hurry···
- 7. If a and B satisfy 3 √ a + 5 √ B = 7, what is the value range of S = 2 √ A-3 √ B?
- 8. If a and B satisfy (3 radical a) + (5|b |) = 7, find the value range of S = (2 radical a) - (3|b |) There should be a reason
- 9. Sn = 1 + 1 / 2 + 1 / 3 +. + 1 / N, f (n) = s2n + 1-sn + 1, f (n) > m is constant, the value range of M is constant
- 10. Sn = 1 + 1 / 2 + 1 / 3 +. + 1 / N, f (n) = s2n + 1-sn + 1, finding f (n) > log2 (m-1) - log (m-1) 2 constant holds, the value range of M
- 11. The nonzero vectors a and B satisfy: | B | = 1, and the angle between B and B-A is 30 degrees. Please give us a detailed explanation
- 12. Given that the plane non-zero vector a and vector b satisfy | vector B | = 1 and the angle between vector a and vector b-vector A is 120 °, what is the value range of | vector a | Seeking ideas and results does not need to write too detailed process, thank you
- 13. It is known that the included angle of non-zero vectors a and B is 60 ° and | a | = | B | = 2. If vector C satisfies (A-C); (B-C) = 0, then | C | = 2? Is to find the value range
- 14. Given that the nonzero vector AB satisfies B = 1 and the angle between B and B-A is 30, then the value range of a is
- 15. If the nonzero vectors a and B satisfy: | B | = 1, and the angle between B and B-A is 60 degrees, the value range of | a |?
- 16. A1 = 1, Sn = nan-n (n-1), the general formula of an
- 17. Given that the sum of the first n terms of the sequence {an} is Sn = n2-2n + 3, then the general term formula of the sequence is______ .
- 18. The general formula of Sn = 2n-n
- 19. It is proved that if an > 0 and lim (n →∞) a (n) / a (n + 1) = l > 1, then LIM (n →∞) a (n) / a (n + 1) = l > 1 It is proved that if an > 0 and lim (n →∞) a (n) / a (n + 1) = l > 1, then LIM (n →∞) = 0
- 20. The proof of the first higher number: if an > 0 and lim (n →∞) a (n + 1) / a (n) = a, then LIM (an ^ (1 / N)) = a Is there a simpler proof