Solving Quadratic Equation with Complex Roots 

                  Lesson 1

                                                                                                                       

                                                   

                                                  Problem:   Solve for the indicated variable and express the roots of the

Equation in simplest a + bi form:

x + 2x + 21 = 0

  

                                                  Solution       x+2x+21=0

Step 1: Solving by Quadratic formula:                                                                         

                                      

                                                  Solution      x= {-b+√ (b-4ac)}/2a

                                                  Step 2:                                                                             

                                                                                 

                                                  Solution      Here, a=1, b=2, c=21

                                                  Step 3:                                                                

 

                                                  Solution      Substituting the given values in above formula:                  

                                                  Step 4:    

 

                                                  Solution      x = {-(2) + √ (2) -4(1) (21)}/2x1

Step 5:  = {-2 + √ (4-84)}/2; (-2 + 4√-5)/2; (-1 + 10i)

                                                   

Solution      Answer: -1 + 10i, -1 - 10i

                                                  Step 6:                                                                  

                                                  Complete                                                                                                                         

                                                   

                                                  Try two practice problems:  

 

                                                                       Do the following:                                                                                      

                                                                              

Solve for the indicated variable and express the roots of the equation in simplest a + bi form:

A.

x+3x+23=0

B.

p/3= 7p+12

                 

 

        

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