Find the sum S of the infinite series Σk=2∞ 9·(2/5)ᵏ.
Sequences & series worksheet with answers
1.Easy
a = 9r = 2/5k₀ = 2
S =
2.Easy
Find the sum S8 of the first 8 terms of the geometric sequence 10, −5, 2.5, …
a₁ = 10r = −0.5n = 8
S8 =
3.Medium
Find the sum S = Σk=137 4/(k(k + 1)).
ak = 4/(k(k + 1))n = 37
S =
4.Medium
Find the radius of convergence R of the power series Σk=1∞ 4ᵏx²ᵏ/k.
Σ 4ᵏx²ᵏ/kx₀ = 0
R =
5.Hard
Use the Maclaurin polynomial of degree 3 of f(x) = sin(3x) to approximate f(0.5). Give P₃(0.5).
f(x) = sin(3x)n = 3x = 0.5
P₃(0.5) =
6.Hard
Recognise the series and find its sum: S = Σk=0∞ (−1)ᵏ/(2k)!.
ak = (−1)ᵏ/(2k)!
S =
Answer key
- 1. S = 2.4
- 2. S8 = 6.641
- 3. S = 3.895
- 4. R = 0.5
- 5. P₃(0.5) = 0.9375
- 6. S = 0.5403
Full step-by-step solutions: practise this topic on examproblems.com.