Q. The common ratio in a geometric series is 4 and the first term is 3 .Find the sum of the first 8 terms in the series.
Identify Formula: Identify the formula for the sum of the first n terms in a geometric series.The sum of the first n terms in a geometric series can be found using the formula:Sn=a⋅(1−rn)/(1−r), where Sn is the sum of the first n terms, a is the first term, r is the common ratio, and n is the number of terms.
Plug Values: Plug the given values into the formula.We are given the first term a=3, the common ratio r=4, and the number of terms n=8. So we substitute these values into the formula:S8=3×(1−48)/(1−4)
Calculate Power: Calculate the power of the common ratio.Calculate 48 to simplify the formula.48=65536
Substitute Value: Substitute the value of 48 back into the formula.S8=3×(1−65536)/(1−4)
Simplify Numerator: Simplify the numerator of the formula.Calculate 1−65536.1−65536=−65535
Simplify Denominator: Simplify the denominator of the formula.Calculate 1−4.1−4=−3
Divide to Find Sum: Divide the numerator by the denominator to find the sum of the first 8 terms.S8=(−3)3×(−65535)
Final Answer: Simplify the expression to find the final answer.S8=3×65535/3S8=65535
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