Find the sum S6 of the first 6 terms of the geometric sequence 3, 6, 12, …
Sequences & series worksheet with answers
1.Easy
a₁ = 3r = 2n = 6
S6 =
2.Easy
Find the sum S33 of the first 33 terms of the arithmetic sequence −12, −9, −6, −3, …
a₁ = −12d = 3n = 33
S33 =
3.Medium
Apply the root test to Σk=1∞ ((2k + 2)/(6k + 5))ᵏ. Find L = lim |ak|1/k.
ak = ((2k + 2)/(6k + 5))ᵏ
L =
4.Medium
Find the radius of convergence R of the power series Σk=1∞ k·3ᵏ·xᵏ.
Σ k·3ᵏ·xᵏx₀ = 0
R =
5.Hard
Use the Maclaurin polynomial of degree 3 of f(x) = 1/(1 − x) to approximate f(0.4). Give P₃(0.4).
f(x) = 1/(1 − x)n = 3x = 0.4
P₃(0.4) =
6.Hard
f(x) = sin x is approximated at x = 0.5 by its Maclaurin polynomial of degree n. With the Lagrange bound M·|x|ⁿ⁺¹/(n + 1)! and M = 1, find the smallest degree n that guarantees an error below 1 × 10⁻⁶.
f(x) = sin xx = 0.5M = 1ε = 1 × 10⁻⁶
n =
Answer key
- 1. S6 = 189
- 2. S33 = 1188
- 3. L = 0.3333
- 4. R = 0.3333
- 5. P₃(0.4) = 1.624
- 6. n = 7
Full step-by-step solutions: practise this topic on examproblems.com.