Week 6- Completing the square/ Quadratic Formula

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In Week 6 of Pre-Calc, we learned about the 3 ways that we can solve a polynomial equation. One way we could solve a polynomial equation was by factoring (Week 5 blog post). The second way that we can sole a polynomial equation was by Completing the Square (irrational roots), and to complete the square you have to put a blank positive and negative space between the 2nd trinomial term and the 3rd trinomial term.

Example: Completing the square

x^2 + 8x + 10=0

 

(\frac{8}{2})^2 = \frac{64}{4}

 

( x^2 + 8x + \frac{64}{4} ) - \frac{64}{4} + 10=0

 

( x^2 + 8x + 16) - 16 + 10=0

 

(x+4)^2 - 6 =0

 

(x+4)^2=6

 

\sqrt {(x+4)^2} = \sqrt {6}

 

x+4= \pm \sqrt {6}

 

x= -4 \pm \sqrt {6}

 

The third way of solving a polynomial equation with a irrational roots would be using the Quadratic Fomula

Example:

 

 

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