Download presentation
Presentation is loading. Please wait.
Published byBrian Whitehead Modified over 9 years ago
1
Solving the Quadratic Equation by Completing the Square
2
43210 In addition to level 3, students make connections to other content areas and/or contextual situations outside of math. Students will factor polynomials using multiple methods, perform operations (excluding division) on polynomials and sketch rough graphs using key features. - Factor using methods including common factors, grouping, difference of two squares, sum and difference of two cubes, and combination of methods. - Add, subtract, and multiply polynomials, - Explain how the multiplicity of the zeros provides clues as to how the graph will behave. - Sketch a rough graph using the zeros and other easily identifiable points. Students will factor polynomials using limited methods, perform operations (excluding division) on polynomials, and identify key features on a graph. - Add and subtract polynomials. - Multiply polynomials using an area model. - Factor polynomials using an area model. - Identify the zeros when suitable factorizations are available. - Identify key features of a graph. Students will have partial success at a 2 or 3, with help. Even with help, the student is not successful at the learning goal. Focus 9 Learning Goal – ( HS.A-SSE.A.1, HS.A-SSE.A.2, HS.A-SEE.B., HS.A-APR.A.1, HS.A- APR.B.3, HS.A-REI.B.4) = Students will factor polynomials using multiple methods, perform operations (excluding division) on polynomials and sketch rough graphs using key features.
3
Complete the square when the leading coefficient is 1. How would you factor x 2 -6x+7=0?
4
Steps to “Completing the Square” 1.Subtract “c” from both sides of the equal sign. 2.Find ( 1 / 2 b) 2 3.Add that value to both sides of the equal sign. 4.Factor the perfect square trinomial. 5.Tip: Substitute the value of “ 1 / 2 b” into the parentheses to make a perfect square trinomial. (x + ___) 2 = {c + ( 1 / 2 b) 2 } 6.Take the square root of both sides. 7.Solve for x.
5
X 2 - 6x =-7 x 2 -6x+7=0 x 2 -6x+9=-7+9 Practice the steps to completing the square. Subtract 7 Make perfect square trinomial Add (½ b) 2 to each side.( 1 / 2 (-6)) 2 = 9
6
(x-3) 2 =2 Take sq. root Two Answers Add 3 to both sides Tip: Put ½ b into the ( ) with sign from original.
7
PRACTICE x 2 +5x-8=0 1. x 2 + 5x = 8 2.( 1 / 2 ∙5) 2 = 25 / 4 = 6¼ 3. x 2 + 5x + 25 / 4 = 8 + 6¼ 4.x 2 + 5x + 25 / 4 = 14¼ 5.(x + 5 / 2 ) 2 = 14¼ 6.x = ± √14 ¼ - 5 / 2
8
Practice: x 2 -4x+2=0 1. x 2 - 4x = -2 2. ( 1 / 2 (-4)) 2 = 4 3. x 2 - 4x + 4 = -2 + 4 4. x 2 - 4x + 4 = 2 5. (x - 2) 2 = 2 6. x = ± √2 + 2
9
Solve when the coefficient isn’t 1! 4x 2 -4x-15=0 Original: divide each term by 4 to get x 2 alone.
10
(x- ) 2 = 4 x = 2 + x = 2 ½ & -1 ½
11
What method is best?
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.