How to Make a Polynomial Trendline in Excel (2 Easy Ways)

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When outcomes rely on multiple conditions or trends, it’s better to insert polynomial trendlines for Excel Charts. Users can make a polynomial trendline in Excel using two or three ways.

Let’s say we have daily Total Revenue amounts that depend on multiple conditions, and we inserted an Excel Chart. Now, we want to insert a polynomial trendline into the Chart.

In this article, we will demonstrate how to use Excel’s Chart Elements option and Polynomial Equation to make a polynomial trendline in Excel.

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Polynomial and Its Expression

2 Easy Ways to Make a Polynomial Trendline in Excel

Method 1: Applying Chart Elements Option to Insert a Polynomial Trendline

Method 2: Using Polynomial Formula to Make a Trendline

Conclusion

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Making a Polynomial Trendline.xlsx

Polynomial and Its Expression

Polynomials are expressions containing variables (i.e., x and y) and coefficients (i.e.,a₀,a₂.. etc.); the expressions allow Arithmetic Operators and positive integer exponentiation. A typical Polynomial Expression is

a₀+a₁x+a₂x²+…+a_n-1x^n-1+a_nxⁿ

2 Easy Ways to Make a Polynomial Trendline in Excel

Use any of the following methods to insert a polynomial trendline in Excel.

Method 1: Applying Chart Elements Option to Insert a Polynomial Trendline

Excel offers a Chart Elements feature after clicking on the Plus icon beside inserted Charts. The Chart Elements feature contains the Trendline option to insert a desired trendline into the Charts.

Step 1: Highlight the columns in the dataset then go to Insert > Click on any of the Chart types (Insert Column or Bar Chart, Insert Line or Area Chart, etc.) (Here, Insert Scatter or Bubble Chart is chosen).

Step 2: After inserting the chart, click on the chart. The side Menu bar opens up. Click on the Plus Icon > Arrow Icon beside Trendline (from Chart Elements options) > More Options.

🔺 You can add the trendline by clicking on Chart > Chart Design > Add Chart Element (from Chart Layouts) > Trendline.

Step 3: Excel fetches the Format Trendline window. Mark Polynomial and type 4 in the Order box under Trendline Options. You can display the polynomial equation on the Chart if the situation demands it.

🔺 Furnish the Chart according to your taste and the outcome may look like the image below.

Method 2: Using Polynomial Formula to Make a Trendline

Polynomial expressions hold variables and constants. You can enter any random variable and constant value. Then use them in the expression to find the outcomes. After getting those resultant values, users can insert the desired Chart and trendline.

Step 1: Enter the random constant values as shown in the picture below.

Step 2: Paste the following formula into the G4 cell.

=$C$4+$C$5*E4+$C$6*E4^2+$C$7*E4^3+$C$8*E4^4

In the formula C4 = a₀C5= a₁ C6= a₂ C7= a₃ C8= a₄

Step 3: Press ENTER, then drag the Fill Handle to execute the formula in other cells.

Step 4: Repeat Steps 1 to 3 of method 1 to insert a Column Chart and Trendline. Afterward, the final depiction will be similar to the below image.

Conclusion

This article demonstrates ways to make a polynomial trendline in Excel using the Chart Elements option and a typical polynomial expression. We hope this article clarifies your understanding of polynomial and its insertion in Excel Charts. Comment if you have further inquiries or have anything to add.