DispatchThursday 4/4/13

Solve the following equation by using the Quadratic Formula

x2 – 5x = – 4

{1,4}

Solving Quadratic Equations

We will be able to determine how many solutions does a given quadratic equation have.

Standard: 22.0

REAL LIFE APPLICATION

Mr. Hernandez went bungee jumping on his recent trip to Cabo San Lucas. Before he decided to jump he thought to himself “Hey, I better make sure that I am high enough to not hit the ground when I jump”. Mr. Hernandez, as the great math genius that he is figured out that the elasticity of the bungee chord created the equation h = t2 – 9t + c, where t represents time and c represents his initial height. What should the value of c be so Mr. Hernandez does not hit the ground?

ACTIVITYSTEP 1:Solve the Quadratic Equation that was assigned to you using the Quadratic Formula in the “My Equation Box”

STEP 2:Have your elbow partner check your answer

STEP 3:As a group, share your answers to complete “My Group Findings” Chart

ACTIVITYSTEP 4:Before asking me to check your answers, check with each other.

STEP 5:Complete the Questions that follow

My Group FindingsEquation Solutions,

X intercepts, Roots

Graph 

x2 + 4x = 5      

   

2x2 + x – 1 = 0      

   

x2 – 4x + 4 = 0      

   

x2 – 6x = – 9      

   

3x2 – 2x + 2 = 0      

   

5x2 – x + 3 = 0      

   

Making ConnectionsWhat relationship (pattern) did you notice between the Quadratic Formula and the number of solutions? (Hint: look at how you solved the problem)

What conclusions can you make about finding the number of solutions in a Quadratic Equation?

How to use the _________________ to determine the number of roots:

 

Value of the ____________:

 

Number of x-intercepts (roots) of ax2 + bx + c =

0

Graph

REAL LIFE APPLICATION

Mr. Hernandez went bungee jumping on his recent trip to Cabo San Lucas. Before he decided to jump he thought to himself “Hey, I better make sure that I am high enough to not hit the ground when I jump”. Mr. Hernandez, as the great math genius that he is figured out that the elasticity of the bungee chord created the equation h = t2 – 9t + c, where t represents time and c represents his initial height. What should the value of c be so Mr. Hernandez does not hit the ground? (Hint: Discriminant)