A ball is dropped and its first rebound reaches 2 m. Every next rebound reaches 90% of the previous one. Which rebound n is the first one lower than 0.1 m?
Sequences & series worksheet with answers
1.Easy
a₁ = 2r = 0.9ε = 0.1
n =
2.Easy
The geometric sequence aₙ = 20·0.5ⁿ⁻¹ decreases. Find the first index n for which aₙ < 0.01.
a₁ = 20r = 0.5ε = 0.01
n =
3.Medium
Find the sum S = Σk=1∞ 5/(k(k + 2)).
ak = 5/(k(k + 2))
S =
4.Medium
Find the sum S = Σk=1∞ 1/(k(k + 3)).
ak = 1/(k(k + 3))
S =
5.Hard
f(x) = eˣ is approximated by its Maclaurin polynomial of degree 5 at x = 1. Use the Lagrange error bound M·|x|ⁿ⁺¹/(n + 1)! with M = e1 = 2.718 to find the largest possible error |R₅|.
f(x) = eˣn = 5x = 1M = 2.718
|R₅| =
6.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 1 × 10⁻⁵.
f(x) = eˣx = 1M = 3ε = 1 × 10⁻⁵
n =
Answer key
- 1. n = 30
- 2. n = 12
- 3. S = 3.75
- 4. S = 0.6111
- 5. |R₅| = 0.003775
- 6. n = 8
Full step-by-step solutions: practise this topic on examproblems.com.