5
4
3
2
Correct answer is D
Sn=n2(2a+(n−1)d
n2(2a+(n−1)d=n2+2n
n(2a+(n−1)d=2n2+4n
2an+n2d−nd=2n2+4n
Comparing the equations, d = 2 (coefficient of n2).
If s=3i−j and t=2i+3j, find (t−3s).(t+3s)....
Marks 5 - 7 8 - 10 11 - 13 14 - 16 17 - 19 20 - 22 Frequency 4 7 26 41 1...
If (p+q10p−q) = \(\begin{pmatrix} 2 & 1 ...
Marks 2 3 4 5 6 7 8 No of students 5 7 9 6 3 6 4 The table above sho...
Find, in surd form, the value of cos165....
If P(x - 3) + Q(x + 1) = 2x + 3, find the value of (P + Q). ...
In how many ways can 9 people be seated on a bench if only 3 places are available? ...