5
4
3
2
Correct answer is D
\(S_{n} = \frac{n}{2}(2a + (n - 1)d \)
\(\frac{n}{2}(2a + (n - 1) d = n^{2} + 2n\)
\(n(2a + (n - 1) d = 2n^{2} + 4n\)
\(2an + n^{2}d - nd = 2n^{2} + 4n\)
Comparing the equations, d = 2 (coefficient of \(n^{2}\)).
If P = \(\begin {pmatrix} 2 & 3\\ -4 & 1 \end {pmatrix}\), Q = \(\begin{pmat...
Simplify \(\frac{x^{3n + 1}}{x^{2n + \frac{5}{2}}(x^{2n - 3})^{\frac{1}{2}}}\)...
Find the stationary point of the curve \(y = 3x^{2} - 2x^{3}\)....
Determine the coefficient of \(x^{2}\) in the expansion of \((a + 3x)^{6}\)...
How many ways can 12 people be divided into three groups of 2, 7 and 3 in that order? ...
Face 1 2 3 4 5 6 Frequency 12 18 y 30 2y 45 Given the table above as t...
The table shows the distribution of the distance (in km) covered by 40 hunters while hunting. ...