How to Solve a Quadratic Equation in Excel

To solve a quadratic equation in Excel, you can use the built-in formula "=QUAD()" or the more versatile "=LINEST()" function. Follow these steps to find the roots of a quadratic equation in Excel:

Using QUAD() function

1. Open Microsoft Excel and create a new spreadsheet.
2. In cell A1, type the coefficient of the squared term (a).
3. In cell A2, type the coefficient of the linear term (b).
4. In cell A3, type the constant term (c).
5. In cell A4, type the following formula: =QUAD(A1, A2, A3)
6. Press Enter, and Excel will calculate the roots of the quadratic equation.

Note: The QUAD() function is only available in Excel 2013 and later versions. If your Excel version doesn't support the QUAD() function, you can use the LINEST() function, as described in the next section.

Using LINEST() function

1. Open Microsoft Excel and create a new spreadsheet.
2. In cell A1, type the coefficient of the squared term (a).
3. In cell A2, type the coefficient of the linear term (b).
4. In cell A3, type the constant term (c).
5. In cell A4, type the following formula: =(-A2+SQRT(A2^2-4*A1*A3))/(2*A1)
6. In cell A5, type the following formula: =(-A2-SQRT(A2^2-4*A1*A3))/(2*A1)
7. Press Enter, and Excel will calculate the roots of the quadratic equation.

Example

Let's solve the quadratic equation 2x^2 - 5x + 3 = 0 using the LINEST() function:

1. Open Microsoft Excel and create a new spreadsheet.
2. In cell A1, type "2" (coefficient of the squared term).
3. In cell A2, type "-5" (coefficient of the linear term).
4. In cell A3, type "3" (constant term).
5. In cell A4, type the following formula: =(-A2+SQRT(A2^2-4*A1*A3))/(2*A1)
6. In cell A5, type the following formula: =(-A2-SQRT(A2^2-4*A1*A3))/(2*A1)
7. Press Enter, and Excel will calculate the roots of the quadratic equation.

The results in cells A4 and A5 are the two roots of the quadratic equation: x = 1 and x = 1.5.