Sum of first 10 terms: \( \frac102 \times (5 + 32) = 5 \times 37 = 185 \) - IQnection
Understanding the Sum of the First 10 Terms Using the Arithmetic Series Formula
Understanding the Sum of the First 10 Terms Using the Arithmetic Series Formula
Calculating the sum of a sequence is a fundamental concept in mathematics, especially when working with arithmetic series. One interesting example involves computing the sum of the first 10 terms of a specific series using a well-known formula โ and it aligns perfectly with \( \frac{10}{2} \ imes (5 + 32) = 5 \ imes 37 = 185 \). In this article, weโll explore how this formula works, why itโs effective, and how you can apply it to solve similar problems efficiently.
Understanding the Context
What Is an Arithmetic Series?
An arithmetic series is the sum of the terms of an arithmetic sequence โ a sequence in which the difference between any two consecutive terms is constant. This constant difference is called the common difference.
For example, consider the sequence:
\( a, a + d, a + 2d, a + 3d, \dots \)
where:
- \( a \) is the first term,
- \( d \) is the common difference,
- \( n \) is the number of terms.
The sum of the first \( n \) terms of such a series is given by the formula:
Image Gallery
Key Insights
\[
S_n = \frac{n}{2} \ imes (2a + (n - 1)d)
\]
Alternatively, it can also be written using the average of the first and last term:
\[
S_n = \frac{n}{2} \ imes (a + l)
\]
where \( l \) is the last term, and \( l = a + (n - 1)d \).
๐ Related Articles You Might Like:
๐ฐ A ball is thrown upward with an initial velocity of 20 m/s from a height of 5 meters. Its height after \( t \) seconds is modeled by \( h(t) = -5t^2 + 20t + 5 \). When does the ball hit the ground? ๐ฐ Set \( h(t) = 0 \): \( -5t^2 + 20t + 5 = 0 \). ๐ฐ Divide by -5: \( t^2 - 4t - 1 = 0 \). ๐ฐ Woodhill 2751815 ๐ฐ Breaking The Silence A Heartbreaking Moment When She Lay Vulnerable In A Hospital Bed 7506309 ๐ฐ Px To Inches 8571414 ๐ฐ You Wont Believe What Happens When You Refinance Your Car Loan 1583860 ๐ฐ Aa Battery Battery 8342677 ๐ฐ You Wont Believe What Happened When Lif Stock Shattered The Market 1000 Overnight 4478787 ๐ฐ These Orc Names Will Scare Every Fantasy Fancheck These Out 5367286 ๐ฐ Bay Pointe Inn 9950007 ๐ฐ Alti O Secret Signal No One Noticesunlock It Now 2168742 ๐ฐ Twinsburg 3691138 ๐ฐ From Lost To Legend In One Instant Watch The Epic Basketball Game That Shocked Fans 1647784 ๐ฐ This Red Shelf Is The Hidden Swap That Every Homeowner Needs In 2024 5979276 ๐ฐ Gluttony Sin 7127957 ๐ฐ Secure The Most Stylish Graduation Gown This Seasonlimited Styles Selling Out Fast 9096126 ๐ฐ Dominican Republic Travel 471360Final Thoughts
Applying the Formula to the Given Example
In the expression:
\[
\frac{10}{2} \ imes (5 + 32) = 5 \ imes 37 = 185
\]
we recognize this as a concise application of the arithmetic series sum formula.
Letโs match the terms to our general strategy:
- \( n = 10 \) โ we want the sum of the first 10 terms
- First term, \( a = 5 \)
- Last term, \( l = 32 \) (which is \( 5 + (10 - 1) \ imes d = 5 + 9 \ imes d \). Since \( d = 3 \), \( 5 + 27 = 32 \))
Now compute:
\[
S_{10} = \frac{10}{2} \ imes (5 + 32) = 5 \ imes 37 = 185
\]
Why This Formula Works
The formula leverages symmetry in the arithmetic series: pairing the first and last terms, the second and second-to-last, and so on until the middle. Each pair averages to the overall average of the sequence, \( \frac{a + l}{2} \), and there are \( \frac{n}{2} \) such pairs when \( n \) is even (or \( \frac{n - 1}{2} \) pairs plus the middle term when \( n \) is odd โ but not needed here).
Thus,
\[
S_n = \frac{n}{2} \ imes (a + l)
\]