【判断题】组合量块时,为减少量块组合的累积误差,应尽量减少量块的组合块数,一般不超过6块 。
【单选题】Mom was singing a lullaby to my baby sister while rocking the cradle with a gentle backwards and forwards ______.
【判断题】量块组合使用时,所选量块的数量一般不超过4块。
【简答题】数列{a n }满足a 1 =1,a n+3 =a n +3,a n+2 ≥a n +2(n∈N * ). (1)求a 7 ,a 5 ,a 3 ,a 6 ; (2)求数列{a n }的通项公式a n ; (3)求证: 1 a 1 2 + 1 a 2 2 + 1 a 3 2 +…+ 1 a n 2 <2 .
【简答题】已知等比数列{a n },若a 1 +a 2 +a 3 =7,a 1 a 2 a 3 =8,求a n .
【简答题】已知等比数列{a n }中,a 1 +a 2 +a 3 =7,a 1 a 2 a 3 =8,求a n .
【简答题】.(1)设向量 a , b 满足| a |=| b |=1及|3 a -2 b |= 7 ,求|3 a + b |的值. (2)在数列{a n }中,已知a 1 =1, 1 a n+1 = 1 a n + 1 2 ,(n∈N + ),求a 50 ..
【简答题】已知(2x-1) 7 =a 7 x 7 +a 6 x 6 +a 5 x 5 +…+a 1 x+a 0 (1)求a 5 ; (2)求a 1 +a 3 +a 5 +a 7 的值.
【简答题】已知等差数列{a n },a 1 +a 3 =8,a 7 =54,求a 1 ,d,a n .