Q. 5. Tentukan jari-jari konvergen deret berikut dengan cara formula Cauchy Hadamard: (bobot 20)n=2∑∞(n−2)3n(z)n
Use Cauchy-Hadamard formula: Use the Cauchy-Hadamard formula to find the radius of convergence, R. The formula is R1=limn→∞∣an∣n1, where an is the nth term of the series.
Identify nth term: Identify the nth term of the series, an=(n−2)3n.
Apply formula: Apply the Cauchy-Hadamard formula: R1=limn→∞∣∣(n−2)3n∣∣n1.
Simplify expression: Simplify the expression: R1=limn→∞((n−2)n13nn).
Calculate radius: Since 3(n/n) is just 3 and (n−2)(1/n) approaches 1 as n approaches infinity, we have R1=13.
Calculate radius: Since 3(n/n) is just 3 and (n−2)(1/n) approaches 1 as n approaches infinity, we have 1/R=3/1. Therefore, R=1/3.
More problems from Sum of finite series not start from 1