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QUADRATICS WITH COMPLEX ROOTS

Unit Overview
In this unit, you will study complex roots of quadratic equations.  Complex roots arise when using the quadratic formula results in taking the square root of a negative number.

 In units 19 and 20, we studied quadratic equations and how to solve them. However, sometimes we may get an equation that we cannot factor.   It may be helpful to review the quadratic formula as well as the discriminant. To review the quadratic formula, click here.  (Unit 20, Quadratic Formula)


Consider:  x2 + 2x+ 5= 0 

 

question1Quick review.  Use the quadratic formula to find the discriminant of the following equation: g(x) = x2 + 10x + 35.

a = 1 b = 10 c = 35

b 2 – 4ac = 102 – 4(1)(35) = 100 – 140 = –40

"Click here" to check the answer.




Stop!  Go to Questions #1-30 for this unit.



Below are additional educational resources and activities for this unit.
 
The Quadratic Formula
 
Understanding the Discriminant