Find the sum S of the infinite series Σk=2∞ 10·(1/3)ᵏ.
Sequences & series worksheet with answers
1.Easy
a = 10r = 1/3k₀ = 2
S =
2.Easy
Find the sum S9 of the first 9 terms of the geometric sequence 2, −1, 0.5, …
a₁ = 2r = −0.5n = 9
S9 =
3.Medium
Apply the ratio test to Σk=1∞ (k!)²·3ᵏ/(2k)!. Find L = lim |ak+1/ak|.
ak = (k!)²·3ᵏ/(2k)!
L =
4.Medium
Find the radius of convergence R of the power series Σk=1∞ (x − 3)ᵏ/5ᵏ.
Σ (x − 3)ᵏ/5ᵏx₀ = 3
R =
5.Hard
Recognise the series and find its sum: S = Σk=1∞ (−1)k+1·0.2ᵏ/k.
ak = (−1)k+1·0.2ᵏ/k
S =
6.Hard
Find the coefficient c₄ of (x − 1)⁴ in the Taylor series of f(x) = 1/x about a = 1.
f(x) = 1/xa = 1k = 4
c₄ =
Answer key
- 1. S = 1.667
- 2. S9 = 1.336
- 3. L = 0.75
- 4. R = 5
- 5. S = 0.1823
- 6. c₄ = 1
Full step-by-step solutions: practise this topic on examproblems.com.