The integral ∫12ex . x22 + logexdx = ?
e(2e - 1)
e(4e + 1)
4e2 - 1
e(4e - 1)
The common difference of the A.P. b1,b2,....,bm is 2 more than common difference of A.P. a1,a2,...,an. If a40 = –159, a100 = – 399 and b100 = a70, then b1is equal to :
127
81
- 127
- 81
D.
Let a1, a1 + d, a1 + 2d ... first A.P.a40 = a1 + 39d = - 159 ...ia100 = a1 + 99d = - 399 ...iifrom equation i and iid = - 4, a1 = - 3nowb100 = a70⇒ b1 + 99D = a1 + 69db1 + 99 × - 2= - 3 + 69 × - 4 (According to question D = d + 2)⇒ b1 = - 81