CLARET SCHOOL OF ZAMBOANGA CITY Ruste Drive, San Jose Road, Zamboanga City High School Mathematics Department Teacher’s Learning Plan in MATHEMATICS IV Name: Yr. & Sec.: Activity Title: Reference: Value: Activity No.: 15 Quarter: First Date:

Quadratic Formula Reference # 2, pp. 184 – 186 EP2: All forms of life are important (Empowerment)

Learning Targets: A. Find the roots of a quadratic equation using the quadratic formula. B. Show positive attitude in dealing personal problems.
I. Concept Notes

Quadratic Formula

For any quadratic equation of the form are

ax 2 + bx + c = 0 , where a ≠ 0 the solutions

x=

− b ± b 2 − 4ac 2a

The quadratic formula gives us another technique to solve a quadratic equation. This method will work regardless of whether the equation is factorable or not factorable. Example: Directions: The column on the left shows the steps used to solve a problem using the quadratic formula. Use the column on the left to answer each question in the column on the right. PROBLEM: Solve by using the quadratic formula. What process will you use to solve the problem?

4x 2 + x = 2
Write in standard form. What is the standard form of the quadratic equation?

4x + x − 2 = 0
2

Find the values of a, b, and c.

a = 4, b = 1, c = −2

Explain how you know which value is a?

Substitute the values into the quadratic formula.

Write the quadratic formula.

x=
Simplify.

− (1) ± (1) 2 − 4(4)(−2) 2(4)
Explain what the symbol ± means.

x=

− 1 ± 1 − (−32) 8 − 1 ± 33 x= 8

II. Learning Experiences A. Test your Understanding Directions: Solve each quadratic equation using the quadratic formula. 1. - x2 = 5x + 8 2. - 9 x2– 8 = - 12x

CLARET SCHOOL OF ZAMBOANGA CITY Ruste Drive, San Jose Road, Zamboanga City High School Computer Education Department Teacher’s Learning Plan in MATHEMATICS IV Name: Yr. & Sec.: Activity Title: