A ball is dropped and its first rebound reaches 10 m. Every next rebound reaches 75% of the previous one. Which rebound n is the first one lower than 0.1 m?
Sequences & series worksheet with answers
1.Easy
a₁ = 10r = 0.75ε = 0.1
n =
2.Easy
Find the sum S of the infinite series Σk=2∞ 10·(−3/4)ᵏ.
a = 10r = −3/4k₀ = 2
S =
3.Medium
Exactly one of the four series converges. Click it.
A: Σ k²/3ᵏB: Σ ln k / kC: Σ (1 + 1/k)ᵏD: Σ 2ᵏ/k³
- 1A: Σ k²/3ᵏ
- 2B: Σ ln k / k
- 3C: Σ (1 + 1/k)ᵏ
- 4D: Σ 2ᵏ/k³
4.Medium
Apply the ratio test to Σk=1∞ k³·2ᵏ/5ᵏ. Find L = lim |ak+1/ak|.
ak = k³·2ᵏ/5ᵏ
L =
5.Hard
f(x) = eˣ is approximated at x = 1 by its Maclaurin polynomial of degree n. With the Lagrange bound M·|x|ⁿ⁺¹/(n + 1)! and M = 3, find the smallest degree n that guarantees an error below 0.0005.
f(x) = eˣx = 1M = 3ε = 0.0005
n =
6.Hard
Recognise the series and find its sum: S = Σk=1∞ k·0.5ᵏ.
ak = k·0.5ᵏ
S =
Answer key
- 1. n = 18
- 2. S = 3.214
- 3. A: Σ k²/3ᵏ
- 4. L = 0.4
- 5. n = 7
- 6. S = 2
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