FOLLOW US:

1 . Distance between two points,

2 . Coordinates of the point divide any line segment,

3 . Area of triangle,

4 . Inclination of line,

5 . Angle between two lines,

6 . Equation of horizontal line,

7 . Equation of vertical line,

8 . Point-slope form of a line,

9 . Two-point form of a line,

10 . Slope-intercept form of a line,

11 . Normal form of a line,

12 . Distance of a point from a line an

13 . Perpendicular distance between two parallel lines

14 . Application of section formula, like centroid

15 . Perpendicular distance between a point and a line

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Important Formulas

(1) . Distance between two points P(x₁,y₁) and Q(x₂,y₂),PQ =  √ [(x₂ - x₁)² + (y₂ - y₁)²]

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(2) .

(3) .

(4) . Area of triangle if the coordinate of vertices are given let P(x₁,y₁),Q(x₂,y₂), R(x₃,y₃) are vertices

=

Note :  if all three points P,Q and R are collinear then the area of triangle will be 0, because three collinear points cannot develop a triangle.

(5) . The angle of a line is measured anticlock-wise through positive x-axis, it is also known as slope or inclination. it is denoted by m or tanθ

(6) . Slope between two point P(x₁,y₁) and Q(x₂,y₂),

m =

y₂ - y₁/x₂ - x₁

Note:    (a). If slope of both the lines will be equal then lines will be parallel, if m₁ = m₂(lines are parallel).

(b). If m₁ m₂ = -1 ,both lines are perpendicular

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(7) . Equation of a line passing through a point x₁,y₁

(y - y₁) = m(x - x₁)

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(8) . A line passing through two point x₁,y₁ and x₂,y₂

(y - y₁) = m(x - x₁)

m =

y₂ - y₁/x₂ - x₁

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(9) . Single slope form or single intercept form

y = mx + c , where m is slope and c is intercept part on y-axis .

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(10) . Double slope form or double intercept form

x/a

+

y/b

= 1

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(11) . General form of equation

ax + by + c = 0

slope form general form of equation = - coefficient of x/ coefficient of y

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(12) .

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(13) . line x = a or x = -a will be vertical lines (parallel to y-axis)

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(14) . Line y = a and y = -a will be horizontal lines (parallel to x-axis)

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