Problem

Evaluate the Summation sum from i=1 to 14 of i^2

The given problem is asking for the calculation of a finite summation. Specifically, it's requesting the evaluation of the sum of the squares of the first fourteen positive integers. The notation indicates that i is the variable of summation, commencing at 1 and increasing by increments of 1 up to and including 14. The expression i^2 represents the square of each integer in this range. Thus, the problem requires determining the sum of 1^2 + 2^2 + 3^2 + ... + 13^2 + 14^2.

$\sum_{i = 1}^{14} ⁡ i^{2}$

Answer

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Solution:

Step 1:

Utilize the standard formula for the sum of squares of the first $n$ natural numbers:

$$\sum_{i = 1}^{n} i^{2} = \frac{n(n + 1)(2n + 1)}{6}$$

Step 2:

Insert the upper limit of the summation into the formula:

$$\frac{14(14 + 1)(2 \cdot 14 + 1)}{6}$$

Step 3:

Commence simplification.

Step 3.1:

Identify and eliminate common factors between numerator and denominator.

Step 3.1.1:

Extract the factor of $2$ from the numerator:

$$\frac{2 \cdot 7(14 + 1)(2 \cdot 14 + 1)}{6}$$

Step 3.1.2:

Remove shared factors.

Step 3.1.2.1:

Factor $2$ from the denominator:

$$\frac{2 \cdot 7(14 + 1)(2 \cdot 14 + 1)}{2 \cdot 3}$$

Step 3.1.2.2:

Cancel out the common factor of $2$:

$$\frac{\cancel{2} \cdot 7(14 + 1)(2 \cdot 14 + 1)}{\cancel{2} \cdot 3}$$

Step 3.1.2.3:

Reformulate the expression:

$$\frac{7(14 + 1)(2 \cdot 14 + 1)}{3}$$

Step 3.2:

Further simplify the numerator.

Step 3.2.1:

Calculate $2 \cdot 14$:

$$\frac{7(14 + 1)(28 + 1)}{3}$$

Step 3.2.2:

Sum up $14 + 1$:

$$\frac{7 \cdot 15(28 + 1)}{3}$$

Step 3.2.3:

Multiply $7$ by $15$:

$$\frac{105(28 + 1)}{3}$$

Step 3.2.4:

Combine $28 + 1$:

$$\frac{105 \cdot 29}{3}$$

Step 3.3:

Finalize the simplification.

Step 3.3.1:

Multiply $105$ by $29$:

$$\frac{3045}{3}$$

Step 3.3.2:

Divide $3045$ by $3$ to get the final result:

$$1015$$

Knowledge Notes:

The problem involves evaluating the sum of squares of the first $n$ natural numbers. The relevant knowledge points include:

  1. Summation Notation: The sigma notation $\sum$ is used to denote the sum of a sequence of numbers. In this problem, we are summing the squares of the first $n$ natural numbers, which is represented as $\sum_{i = 1}^{n} i^{2}$.

  2. Sum of Squares Formula: The formula for the sum of the squares of the first $n$ natural numbers is given by:

    $$\sum_{i = 1}^{n} i^{2} = \frac{n(n + 1)(2n + 1)}{6}$$ This is a well-known result in mathematics and is used to quickly calculate the sum without having to add each square individually.

  3. Algebraic Simplification: The process involves algebraic manipulation to simplify the expression. This includes factoring out common factors, canceling terms, and performing arithmetic operations such as multiplication and addition.

  4. Arithmetic Operations: Basic arithmetic operations鈥攁ddition, multiplication, and division鈥攁re used to simplify the expression to get the final result.

Understanding these concepts is crucial for solving summation problems efficiently and is a fundamental part of algebra and discrete mathematics.

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