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1.Number System
14-
Lecture1.1
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Lecture1.2
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Lecture1.3
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Lecture1.4
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Lecture1.5
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Lecture1.6
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Lecture1.7
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Lecture1.8
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Lecture1.9
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Lecture1.10
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Lecture1.11
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Lecture1.12
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Lecture1.13
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Lecture1.14
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2.Polynomials
10-
Lecture2.1
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Lecture2.2
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Lecture2.3
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Lecture2.4
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Lecture2.5
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Lecture2.6
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Lecture2.7
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Lecture2.8
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Lecture2.9
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Lecture2.10
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3.Coordinate Geometry
8-
Lecture3.1
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Lecture3.2
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Lecture3.3
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Lecture3.4
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Lecture3.5
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Lecture3.6
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Lecture3.7
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Lecture3.8
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4.Linear Equations
8-
Lecture4.1
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Lecture4.2
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Lecture4.3
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Lecture4.4
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Lecture4.5
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Lecture4.6
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Lecture4.7
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Lecture4.8
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5.Euclid's Geometry
7-
Lecture5.1
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Lecture5.2
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Lecture5.3
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Lecture5.4
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Lecture5.5
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Lecture5.6
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Lecture5.7
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6.Lines and Angles
10-
Lecture6.1
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Lecture6.2
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Lecture6.3
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Lecture6.4
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Lecture6.5
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Lecture6.6
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Lecture6.7
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Lecture6.8
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Lecture6.9
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Lecture6.10
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7.Triangles
11-
Lecture7.1
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Lecture7.2
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Lecture7.3
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Lecture7.4
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Lecture7.5
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Lecture7.6
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Lecture7.7
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Lecture7.8
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Lecture7.9
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Lecture7.10
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Lecture7.11
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8.Quadrilaterals
13-
Lecture8.1
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Lecture8.2
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Lecture8.3
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Lecture8.4
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Lecture8.5
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Lecture8.6
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Lecture8.7
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Lecture8.8
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Lecture8.9
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Lecture8.10
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Lecture8.11
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Lecture8.12
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Lecture8.13
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9.Area of Parallelogram
11-
Lecture9.1
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Lecture9.2
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Lecture9.3
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Lecture9.4
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Lecture9.5
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Lecture9.6
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Lecture9.7
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Lecture9.8
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Lecture9.9
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Lecture9.10
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Lecture9.11
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10.Constructions
7-
Lecture10.1
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Lecture10.2
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Lecture10.3
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Lecture10.4
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Lecture10.5
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Lecture10.6
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Lecture10.7
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11.Circles
11-
Lecture11.1
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Lecture11.2
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Lecture11.3
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Lecture11.4
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Lecture11.5
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Lecture11.6
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Lecture11.7
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Lecture11.8
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Lecture11.9
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Lecture11.10
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Lecture11.11
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12.Heron's Formula
8-
Lecture12.1
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Lecture12.2
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Lecture12.3
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Lecture12.4
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Lecture12.5
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Lecture12.6
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Lecture12.7
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Lecture12.8
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13.Surface Area and Volume
16-
Lecture13.1
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Lecture13.2
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Lecture13.3
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Lecture13.4
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Lecture13.5
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Lecture13.6
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Lecture13.7
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Lecture13.8
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Lecture13.9
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Lecture13.10
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Lecture13.11
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Lecture13.12
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Lecture13.13
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Lecture13.14
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Lecture13.15
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Lecture13.16
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14.Statistics
15-
Lecture14.1
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Lecture14.2
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Lecture14.3
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Lecture14.4
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Lecture14.5
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Lecture14.6
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Lecture14.7
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Lecture14.8
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Lecture14.9
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Lecture14.10
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Lecture14.11
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Lecture14.12
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Lecture14.13
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Lecture14.14
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Lecture14.15
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15.Probability
8-
Lecture15.1
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Lecture15.2
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Lecture15.3
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Lecture15.4
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Lecture15.5
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Lecture15.6
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Lecture15.7
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Lecture15.8
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Chapter Notes – Linear Equations
(1) An equation of the form ax+by+c=0, where a, b, c are real numbers such that a and b not both zero is called a linear equation in two variables.
For Example: 2x+3y+5=0, where a=2, b=3 which are not zero. So this is linear equation in two variables.
(2) A linear equation in two variables has infinitely many solutions.
For Example: we have 4x−y−3=0, there is many solution
If we take x=1 , y=1 then LHS=4×1−1−3=0=RHS
If we take x=2 , y=5 then LHS=4×2−5−3=0=RHS
(3) The graph of a linear equation in two variables is a straight line.
For Example:
x+y=4
We have x+y=4⇒y=4−x
When x=0, we have: y=4−0=4
When x=2, we have: y=4−2=2
When x=4, we have: y=4−4=0
Thus, we have the following table:Plotting the points (0, 4) (2, 2) and (4, 0) on the graph paper and drawing a line joining them.
(4) The equations of x and y-axes are y=0 and x=0 respectively.
For Example:
x+3=0 equation is for x-axes because in this equation y=0.
7y−3=0 equation is for y-axes because in this equation x=0.
(5) The graph of the equation x=a is a straight line parallel to y-axis.
For Example:
The equation for such a line x=−92 is given below:
(6) The graph of the equation y=a is a straight line parallel to x-axis.
For Example: For a line that is parallel to the x-axis, the equation for such a line y=2 is given below:
(7) Every point on the graph of a linear equation in two variables is a solution of the equation. Conversely, every solution of linear equation in two variables represents a point on the graph of the equation.
For Example: In linear equation f(x)=x+2y−1=0 , (3,−1) also lies on this line.