Solving Quadratic Equations by Graphing
Quadratic Equation- A quadratic function set equal to a value, in the form ax 2 +bx+c, where a≠0 Standard Form- A quadratic equation written in the form ax 2 +bx+c, where a,b, and c are integers, and a≠0 Root- The solutions of a quadratic equation Zero- The x-intercepts of the graph of a quadratic equation, the points for which f(x)=0
Find the axis of symmetry Find the ordered pair at the vertex Make a table of values with the vertex in the middle Plot the points from the table
Real solutions are the points on the graph where it crosses the x-axis. Y-value should always be 0 Solutions are in terms of x values
After you have graphed the equation, if the parabola crosses the x-axis twice, you have two real solutions.
After you have graphed the equation, if the parabola touches the x-axis, but does not cross it, then you have one real solution.
After you have graphed the equation, if the parabola does not cross or touch the x-axis, then you have no real solutions.
Turn Calculator on Press y= button Enter equation Press GRAPH button Press 2 nd button, then press TRACE button Select option 2:zero Select point on graph left of zero Select point on graph right of zero Press enter Repeat steps 5-9 as needed
(x+2)(x-5) (x-1)(x+3) (x-2)(x-3) (x+1)(x+4)
Use a quadratic equation to find two real numbers that satisfy each situation, or show that no such numbers exist. Sum is 5, product is -14 Sum is -8, product is 12 Sum is 4, product is 4
Worksheet 5-2