In a series, $T_{n} = 2 n + 5$ , find $S_{4}$ .

Open in App

Solution

$T_{n} = 2 n + 5$
$T_{1} = 2 (1) + 5 = 7; T_{2} - 2 (2) + = 9$
$T_{3} = 2 (3) + 5 = 11; T_{4} = 2 (4) + 5 = 12$
$S_{4} = T_{1} + T_{2} + T_{3} + T_{4} = 7 + 9 + 11 + 13 = 40$

Suggest Corrections

Similar questions

In a series if (i) T_n = 2n − 1 find S₅ (ii) T_n = (−1)ⁿ then find (a) S₁ (b) S₂ (c) S₃ (d) S₄

Hence prove that S₁ = S₃ and S₂ = S₄

T_{n} = 5 n - 2

S_{4}

S_{2} : S_{4}

t_{n} = 5 - 2 n

t_{n - 1} =

t_{n = 2 n - 5}

Join BYJU'S Learning Program