In Problems 39– 44, find each sum.

k=1n23k

Short Answer

Expert verified

The sum of the given sequence is2·1-23n

Step by step solution

01

Step 1. Write the given information.

The given isk=1n23k

02

Step 2. Find the common ratio.

a1=23,a2=232,a3=233a2a1=23223=23a3a2=233232=23r=23

03

Step 3. Find the sum.

The formula for the sum is

sn=a1(1-rn)1-rsn=23·1-23n1-23=23·1-23n13=2·1-23n

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