4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x +...

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4.8 Do Now: practice of 4.8 Do Now: practice of 4.7 4.7 area of a rectangle is 50. If the widt d the length is x + 10. Solve for x by leting the square.

Transcript of 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x +...

Page 1: 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x + 10. Solve for x by completing the square.

4.8 Do Now: practice of 4.74.8 Do Now: practice of 4.7The area of a rectangle is 50. If the width isx and the length is x + 10. Solve for x bycompleting the square.

Page 2: 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x + 10. Solve for x by completing the square.

Algebra IIAlgebra II4.8: Quadratic Formula4.8: Quadratic Formula

HW: p.296 (16, 20, 32, 34)HW: p.296 (16, 20, 32, 34)

Test 4.5, 4.7, 4.8, word problems: Test 4.5, 4.7, 4.8, word problems: Wednesday, Nov. 5Wednesday, Nov. 5thth

Page 3: 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x + 10. Solve for x by completing the square.

Quadratic FormulaQuadratic Formula The quadratic formula is used to solve any The quadratic formula is used to solve any

quadratic equation. quadratic equation.

Quadratic Formula: If axQuadratic Formula: If ax22 + bx + c = 0, + bx + c = 0, thenthen

Page 4: 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x + 10. Solve for x by completing the square.

DiscriminantDiscriminant The discriminant = bThe discriminant = b22 – 4ac – 4ac

The value of the discriminant tells you how The value of the discriminant tells you how many solutions the quadratic equation has.many solutions the quadratic equation has. 0 0 1 real solution. 1 real solution. positive number positive number 2 real solutions. 2 real solutions. negative number negative number 2 imaginary solutions. 2 imaginary solutions.

Page 5: 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x + 10. Solve for x by completing the square.

Find the discriminant and Find the discriminant and determine the number of solutions.determine the number of solutions.

1.) x1.) x22 – 8x + 16 = 0 – 8x + 16 = 0

2.) 5x2.) 5x22 + 20x = -21 + 20x = -21

Page 6: 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x + 10. Solve for x by completing the square.

Use the Quadratic Formula to find Use the Quadratic Formula to find the solutions to the equation.the solutions to the equation.

1.) x1.) x22 – 4x – 5 = 0 – 4x – 5 = 0

Page 7: 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x + 10. Solve for x by completing the square.

Use the Quadratic Formula to find Use the Quadratic Formula to find the solutions to the equation.the solutions to the equation.

2.) 3 – 8v – 5v2.) 3 – 8v – 5v22 = 2v = 2v

Page 8: 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x + 10. Solve for x by completing the square.

4.8: Use the Quadratic Formula to 4.8: Use the Quadratic Formula to find the solutions to the equation.find the solutions to the equation.

3.) 4x3.) 4x22 + 3 = x + 3 = x22 – 7x – 7x

Page 9: 4.8 Do Now: practice of 4.7 The area of a rectangle is 50. If the width is x and the length is x + 10. Solve for x by completing the square.

4.8: Use the Quadratic Formula to 4.8: Use the Quadratic Formula to find the solutions to the equation.find the solutions to the equation.

4.) 4x4.) 4x22 + 3x – 12 = 3 – 3x + 3x – 12 = 3 – 3x