Find the sum of the first 10 terms of the following sequence. Round to the nearest hundredth if necessary.12,2,31,…Sum of a finite geometric series:Sn=1−ra1−a1rnAnswer:
Q. Find the sum of the first 10 terms of the following sequence. Round to the nearest hundredth if necessary.12,2,31,…Sum of a finite geometric series:Sn=1−ra1−a1rnAnswer:
Identify terms and values: First, identify the first term a1, the common ratio r, and the number of terms n in the sequence.The first term a1 is 12.The second term is 2, so the common ratio r can be found by dividing the second term by the first term: r=122=61.The number of terms n we want to find the sum of is 10.
Calculate common ratio: Now, use the formula for the sum of the first n terms of a geometric series: Sn=1−ra1−a1⋅rn Plug in the values we have: a1=12, r=61, and n=10.
Use formula for sum: Calculate the value of rn(61)10. This requires a calculator or a software tool to find the precise value.
Calculate rn: After calculating (61)10, we find that it is a very small number (approximately 1.65381717×10−8).For practical purposes, when subtracting this value from 12 in the numerator, it will have an insignificant effect, so we can approximate the numerator to be just 12.
Approximate numerator: Now, calculate the denominator (1−r)=(1−61)=65.
Calculate denominator: Finally, calculate the sum S10 using the approximated numerator and the calculated denominator:S10≈(12−0)/(65)S10≈12/(65)S10≈12×(56)S10≈14.4
More problems from Find trigonometric functions using a calculator