Question

Write out the sums. (You do not need to evaluate them.) \(\sum_{k=0}^{5}(3 k+1)\)

Short answer

Question: Write out the sums without evaluating them for the expression \(\sum_{k=0}^{5}(3 k+1)\). Answer: \(\sum_{k=0}^{5}(3 k+1)= 1 + 4 + 7 + 10 + 13 + 16\)

Step-by-step solution

Understand the Given Expression

The given expression is a finite summation: \(\sum_{k=0}^{5}(3 k+1)\). Here, the variable \(k\) is the index of summation, and the summation ranges from \(k=0\) to \(k=5\). The summand is the expression \((3 k+1)\), which must be written out for each value of \(k\) within the specified range.

Write Out the Terms

To write out the sums, replace the variable \(k\) with the values ranging from 0 to 5 in the summand expression \((3k + 1)\): - When \(k=0\), the term is \((3(0) + 1)=1\). - When \(k=1\), the term is \((3(1) + 1)=4\). - When \(k=2\), the term is \((3(2) + 1)=7\). - When \(k=3\), the term is \((3(3) + 1)=10\). - When \(k=4\), the term is \((3(4) + 1)=13\). - When \(k=5\), the term is \((3(5) + 1)=16\).

Write Down the Written Out Sums

Now that we've found the terms for each value of \(k\), we can write the sums as follows: \(\sum_{k=0}^{5}(3 k+1)= 1 + 4 + 7 + 10 + 13 + 16\)

Key concepts

finite series

A finite series refers to the sum of a sequence of numbers that has a specific number of terms. Unlike infinite series, which go on indefinitely, finite series stop after a certain point. In mathematical notation, a finite series is expressed using the summation symbol \(\Sigma\). For example, in the expression \(\sum_{k=0}^{5}(3k+1)\), we are faced with a finite series because the addition involves a limited number of terms, specifically six terms, as indicated by the index of summation from 0 to 5.

Understanding finite series is crucial because it allows us to add numerous terms efficiently. Instead of writing or computing each value individually, the summation notation provides a compact and convenient way to express the process. This method is prevalent in mathematics whenever we need to handle a fixed number of additive terms in various contexts like arithmetic and geometric series.

When dealing with finite series, it’s essential to identify:

• The range - how many times you’re adding.
• The pattern of terms - what changes with each addition based on the expression.

index of summation

The term 'index of summation' describes the variable in a summation notation that tells us which values to use in the series. It essentially acts as a counter that runs through a sequence of numbers during the process of summation.

The role of the index of summation in a series is vital:

• It specifies the starting and ending points of the summation.
• It informs how many terms are included in the sum.

For the expression \(\sum_{k=0}^{5}(3k+1)\), the index of summation is \(k\). This means we replace \(k\) with integers from the start 0 to the end 5, determining the amount of terms.

Typically, the index of summation:

• Starts with a declaration of its initial value (in this case, 0).
• Ends at a specified upper limit (here, 5).

This clarity in notation allows us to compute the required series while maintaining a systematic approach.

mathematical expression

A mathematical expression in the context of summation notation is the function or formula, known as the summand, that governs each term being added. It often contains variables, numerical constants, and operations.

In \(\sum_{k=0}^{5}(3k+1)\), the mathematical expression or summand is \(3k+1\). This means for every specific integer value of \(k\) from the index of summation, a new term in the series will be calculated using this expression.

Important aspects of a mathematical expression within a summation include:

• The way it transforms the variable \(k\) with each term.
• How constants affect each term of the series uniformly (e.g., the constant 1 adds an additional amount to every computed term in (3k+1)).

The effective understanding of the summand is essential to ensure accurate series calculations, whether determining each separate term or comprehending the collective mathematical behavior.