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Chapter 1.4. Quadratic Equations. Quadratic Equation in One Variable. An equation that can be written in the form ax 2 + bx + c = 0 where a, b, and c, are real numbers, is a quadratic equation.
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Chapter 1.4 Quadratic Equations
Quadratic Equation in One Variable An equation that can be written in the form ax2 + bx + c = 0 where a, b, and c, are real numbers, is a quadratic equation
A quadratic equation is a second-degree equation—that is, an equation with a squared term and no terms of greater degree. x2 =25, 4x2 + 4x – 5 = 0, 3x2 = 4x - 8
A quadratic equation written in the form ax2 + bx + c = 0 is in standard form.
Solving a Quadratic Equation Factoring is the simplest method of solving a quadratic equation (but one not always easily applied). This method depends on the zero-factor property.
Zero-Factor Property If two numbers have a product of 0 then at least one of the numbers must be zero If ab= 0 then a = 0 or b = 0
Example 1. Using the zero factor property. Solve 6x2 + 7x = 3
A quadratic equation of the form x2 = k can also be solved by factoring. x2 = k x2 – k=0
Square root property If x2 = k, then
Example 2 Using the Square Root Property Solve each quadratic equation. x2 = 17
Example 2 Using the Square Root Property Solve each quadratic equation. x2 = -25
Example 2 Using the Square Root Property Solve each quadratic equation. (x-4)2 = 12
Completing the Square Any quadratic equation can be solved by the method of completing the square.
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 3 Using the Method of Completing the Square, a = 1 Solve x2 – 4x – 14 = 0
Example 4 Using the Method of Completing the Square, a ≠1 Solve 9x2 – 12x – 1 = 0
Example 4 Using the Method of Completing the Square, a ≠1 Solve 9x2 – 12x – 1 = 0
Example 4 Using the Method of Completing the Square, a ≠1 Solve 9x2 – 12x – 1 = 0
Example 4 Using the Method of Completing the Square, a ≠1 Solve 9x2 – 12x – 1 = 0
Example 4 Using the Method of Completing the Square, a ≠1 Solve 9x2 – 12x – 1 = 0
Example 4 Using the Method of Completing the Square, a ≠1 Solve 9x2 – 12x – 1 = 0
Example 4 Using the Method of Completing the Square, a ≠1 Solve 9x2 – 12x – 1 = 0
Example 4 Using the Method of Completing the Square, a ≠1 Solve 9x2 – 12x – 1 = 0
Example 4 Using the Method of Completing the Square, a ≠1 Solve 9x2 – 12x – 1 = 0
The Quadratic Formula Watch the derivation
Example 5 Using the Quadratic Formula (Real Solutions) Solve x2 -4x = -2
Example 6 Using the Quadratic Formula (Non-real Complex Solutions) Solve 2x2 = x – 4
Example 7 Solving a Cubic Equation Solve x3 + 8 = 0
Example 8 Solving a Variable That is Squared Solve for the specified variable.
Example 8 Solving a Variable That is Squared Solve for the specified variable.