EQUATIONS OF LINES

Question 1

general form of an equation

Answer 1

Ax+By+C=0

• A, B, AND C are constants
• NOT BOTH A AND B ARE 0

Question 2

slope intercept form of an equation

Answer 2

y=mx+b

• m is the slope
• b is the y intercept

Question 3

point slope form

*use this when you want to obtain the equation of a line given its slope and one of its points

Answer 3

y-y₁=m(x-x₁)

• x₁ and y₁ is a given point
• m is the slope
• isolate y

Question 4

two point form

*used when we want to obtain the equation of a line given two distinct points on it

Answer 4

y-y₁=y₂−y₁/x₂−x₁(x−x₁)

• where (x₁,y₁) and (x₂,y₂) are any two given points
• the equation y₂−y₁/x₂−x₁ just replaced the m in the point slope form

Question 5

the intercept form of an equation of a line is

Answer 5

x/a + y/b =1

*where a and b are the x an y intercepts respectively