If 1 + 2 + 3 + . . . + n = k then 13 + 23 + … + n3is equal to

Q20 of 110 Page 65

If 1 + 2 + 3 + . . . + n = k then 1³ + 2³ + … + n³is equal to

Sum of first n natural numbers is S = = k

Sum of first n natural squares is S =

Which is k²

So the correct option is A.

In a G.P, t₂ = and t₃ = . Then the common ratio is

If x 0, then 1 + sec x + sec²x + sec³x + sec⁴x + sec⁵x is equal to

If the n^thterm of an A.P. is t_n = 3-5n, then the sum of the first n terms is

The common ratio of the G.P. a^m-n, a^m, a^{m + n}is

Questions · 110

2. Sequences and series of real numbers

1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 1 1 1 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 2 3 4 5 6 7 8 9 10 11 12 1 1 1 1 1 1 2 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20