Download presentation
Presentation is loading. Please wait.
1
10-3: Solving Quadratic Equations
Essential Questions: How many solutions does a quadratic equation have? How can you determine the number of solutions from the graph?
2
10-3: Solving Quadratic Equations
The equation x2 + 3x – 4 = 0 is called a quadratic equation. It’s related to the quadratic function y = x2 + 3x – 4 The solutions of a quadratic equation and the x-intercepts of the quadratic function are the same A quadratic equation can have one, two, or no real-number solutions. The solutions of a quadratic equation and the x-intercepts are often called the roots of the equation or zeros of the function.
3
10-3: Solving Quadratic Equations
Example 1a: Solving by Graphing (Two solutions) Solve each equation by graphing the related function x2 – 4 = 0 Graph y = x2 – 4 Solutions are where the graph crosses the x-axis. There are two solutions here x = 2 or x = -2, which can be written as x = ±2
4
10-3: Solving Quadratic Equations
Example 1b: Solving by Graphing (1 solution) Solve each equation by graphing the related function x2 = 0 Graph y = x2 Solutions are where the graph crosses the x-axis. There is one solution here x = 0
5
10-3: Solving Quadratic Equations
Example 1c: Solving by Graphing (0 solutions) Solve each equation by graphing the related function x2 + 4 = 0 Graph y = x2 + 4 Solutions are where the graph crosses the x-axis. Since the graph never crosses the x-axis, there is no solution
6
10-3: Solving Quadratic Equations
Solving Quadratic Equations Using Square Roots We can solve equations in the form x2 = c by finding the square roots of each side. Solve 2x2 – 98 = 0 2x2 – 98 = Add 98 to each side 2x2 = 98 ÷ ÷2 Divide each side by 2 x2 = 49 x = ± Take the square root of 49 x = ±7 Remember the ±
7
10-3: Solving Quadratic Equations
Your Turn: Solve each equation t2 – 25 = 0 t = ±5 3n = 12 n = 0 2g = 0 No solution
8
10-3: Solving Quadratic Equations
Assignment Worksheet #10-3 Problems 1 – 29, odds
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.