6. Learning Objectives
determine the
roots of a
quadratic
equation by
extracting the
square roots
solve quadratic
equation by
extracting the
square roots
display accuracy
in solving
quadratic
equations by
extracting the
square roots
10. 1. How did you find
each square root? 2. How many square
root does a number
have? Explain your
answer.
Questions:
3. Does a negative
number have a square
root? Why?
12. If , when k is a
real number, then
Square Root Property
13. Roots/Solution of Quadratic Equation in
Extracting the Square Roots
1. If , then has two real solutions or roots:
2. If , then has one real solution or root:
x
3. If , then has no real solutions or roots.
14. Steps in Solving Quadratic Equations by Extracting
the Square Roots
1. Transform the given in the form of
2. Simplify the equation so that only the
term with variable remains on the left
side of that equation
3. Extract the roots of both sides
of the equation
4. Check your answer
16. STEP 1: Transform the given in the form of
Example 1:
𝒙 𝟐
−𝟏𝟔=𝟎Apply Addition Property of Equality
𝒙𝟐
−𝟏𝟔+𝟏𝟔=𝟎+𝟏𝟔
𝒙 𝟐
=𝟏𝟔
Or simply transpose 16 to the other side
𝒙 𝟐
−𝟏𝟔=𝟎
𝒙 𝟐
=𝟏𝟔
Example 1:
Example 1:
17. STEP 2: Simplify the equation so that only the term
with variable remains on the left side of that equation
Example 1:
𝒙 𝟐
=𝟏𝟔
Since 16 is greater than 0, then has two real solutions
or roots. (property 1)
Example 1:
18. STEP 3: Extract the roots of both sides of the equation
Example 1:
𝒙 𝟐
=𝟏𝟔
√ 𝒙 𝟐
=± √𝟏𝟔
𝒙 =± 𝟒 ¿ 𝒙=+ 𝟒∧𝒙=−𝟒
Example 1:
19. STEP 4: Check your answer
Example 1:
𝒙=𝟒 𝒙=− 𝟒
Checking:
For
𝒙 𝟐
−𝟏𝟔=𝟎
(𝟒)𝟐
−𝟏𝟔=𝟎
𝟏𝟔−𝟏𝟔=𝟎
𝟎=𝟎
𝒙 𝟐
−𝟏𝟔=𝟎
For
(− 𝟒)𝟐
−𝟏𝟔=𝟎
𝟏𝟔−𝟏𝟔=𝟎
𝟎=𝟎
Both values of x satisfy the given equation.
So, the equation is true when x = 4 or when x= -4
22. STEP 1: Transform the given in the form of
Example 1:
𝒙 𝟐
+ 𝟗=𝟎Apply Addition Property of Equality
𝒙 𝟐
+ 𝟗− 𝟗=𝟎− 𝟗
𝒙 𝟐
=− 𝟗
Or simply transpose 9 to the other side
𝒙 𝟐
=− 𝟗
Example 1:
Example 3:
𝒙 𝟐
+ 𝟗=𝟎
23. STEP 2: Simplify the equation so that only the term
with variable remains on the left side of that equation
𝒙 𝟐
=− 𝟗
Since -9 is less than 0,
then (property No. 2)
Example 1:
Example 1:
Example 3:
Answer: The equation has no real solutions
24. STEP 1: Transform the given in the form of
Example 1:
(𝒙 − 𝟒)𝟐
− 𝟐𝟓=𝟎 Apply Addition Property of Equality
(𝒙 − 𝟒)𝟐
− 𝟐𝟓+𝟐𝟓=𝟎+𝟐𝟓
( 𝒙 − 𝟒)𝟐
=𝟐𝟓
Or simply transpose -25 to the other side
Example 1:
Example 4:
(𝒙 − 𝟒)𝟐
− 𝟐𝟓=𝟎
(𝒙 − 𝟒)𝟐
=𝟐𝟓
25. STEP 3: Extract the roots of both sides of the equation
√(𝒙−𝟒)
𝟐
=±√𝟐𝟓
𝒙 − 𝟒=± 𝟓 ¿ 𝒙 − 𝟒=+𝟓∧𝒙 − 𝟒=− 𝟓
Example 1:
Example 1:
Example 4:
26. Find the solutions of
the equation by
extracting square
roots.
Find the
solutions of the
equation
.
Each group must pick a problem then allow them to
solve and present their answer to the class.
Solve the
equation .
Find the
solutions of the
equation .
27. 1. What process are you going to use
in solving quadratic equations if the
given equations are in the form of ?
2. How many solutions does a
quadratic equation have in the form
of if the
k >0 ? k = 0? k <0 ?
Generalizations:
28. SOLVE
Solve the following quadratic equation by
extracting the square root. Show your
solutions and box your final answer. (2
points each)
6.
7.
8.
9.
10.
31. Learning Objectives
Identify the
roots of a
quadratic
equations by
factoring
solve quadratic
equation by
factoring
Show patience
and accuracy in
solving quadratic
equations by
factoring
33. 4 𝑥 + 20 𝑥 2
Give the factors of the following
polynomials.
𝑠2
+ 8 𝑠 + 12
34. 1. How did you factor each
polynomial?
Answer the following questions:
3. How would you know if
the factors you got are
correct ones?
35. Steps in Solving Quadratic Equations by Factoring
1. Transform the given equation in the form of
2. Factor the quadratic expression on
the left side of the equation.
3. Apply the Zero Product Property by
equating the two factors of quadratic
equation to 0.
5. Check your answers.
4. Find the values of the variable by
solving the two equations
36. If the product of two real number is zero,
then either of two is equal to zero or both
numbers are equal to zero
(x)(y)=0 if and only if x= 0 or y = 0
Please take note that Zero Product Property will
only be used if the right side of the equation is
equal to zero.
Zero Product Property
38. Find the solution
of
Find the solution
of
Each group must pick a problem then allow them to
solve and present their answer to the class.
Find the solution
of
39. Activity
Solve the following quadratic equation by
factoring. Show your solutions and box your
final answer. (2 points each)
6.
7.
8.
9.
10.