Урок "The quadratic inequalities." 8 класс

M.Kh.Dulati specialized gymnasium #8

for gifted children with teaching in three languages

Teacher: Pavlenko Yelena Valeryevna

Algebra

Grade 8

Theme: The quadratic inequalities.

Aims:

• To develop pupils’ quick wit and logical thinking.

• To make pupils’ work effective through variety of exercises.

• To develop pupils’ skills of solving the quadratic inequalities.

• To check up the use of different ways of solving the quadratic inequalities.

Aids: interactive blackboard, activevote, whiteboard.

Type: revision lesson

Plan

I. Org.moment

II. Warm-up. To begin with let’s answer the questions.

Answer the questions.

1. Give the formula of the discriminant, if b is an odd number

2. Give the formula of the discriminant, if b is an even number

3. Viet theorem

4. The inequalities are called quadratic if…

5. The formula of factoring of quadratic trinomial

III. Find the graphic solution of

1)D0

2) D

3)D=0

IV. Test.

1. Find the roots of equation (B)

A) x=2, x=3

B) x=1,x=-6

C) x=-1,x=-6

D) x=-1,x=6

2. The graph of equation is… (C)

A) Liner

B) Cubic parabola

C) Parabola

D) Hyperbola

3. The domain of function is …(A)

A)

B)

C)

D)

4. Factor the trinomial (A)

A) 2(x-1)(x-1.5)

B) (x-1)(x-1.5)

C) 2(x-1)(x-3)

D) 2(x+1)(x+1.5)

5. Find the right solution of inequality (C)

A)

B)

C)

D)

V. Find the mistakes in the given solution

I v

II v

VI. Find two different solutions of the inequality:

VII. Solve the problem.

The area of the right-angled triangle A is greater than the area of the rectangle B. Find the range of possible values of x.

Solution:

The area of the right-angled triangle is

The area of the rectangle is

As

Factor the left part of inequality (find the common factor)

The side of triangle and rectangle cannot be equal 0 and negative number, so

Thus the range of possible values of x is

Answer:

VIII. Find the domain of functions;

a)

b)

IX. Home-task: book p.112-116 (test)

The others you will get another mark at the next lesson.

Thank you for the lesson!

Evaluation sheet. Algebra 8.Grade __________. Date____________ Student_______________________
#	Task	Points
1.	Find the graphic solution of
2.	Test 1 2 3 4 5
3.	Find the mistakes in the given solution
4.	Find two different solutions of the inequality
5.	Solve the problem.
6.	Find the domain of functions;
Total
Mark