Straight lInes

Question 1

m =

Answer 1

(y2 - y1)/(x2 - x1)

Question 2

tanθ for acute angles=

Answer 2

mod [(m2 - m1)/1+m1m2]

Question 3

when are 2 lines parallel?

Answer 3

if slopes are equal

Question 4

when are 2 lines perpendicular?

Answer 4

if m1m2 = -1

Question 5

equation of vertical line having dist b from y axis is

Answer 5

x=±b

Question 6

equation of horizontal line having dist b from x axis is

Answer 6

y=±a

Question 7

point slope form

Answer 7

m = y-y(0)/x-x(0)

Question 8

two point form

Answer 8

y - y1 = ((y2-y1)/(x2-x1))(x-x1)

Question 9

slope intercept form

Answer 9

y=mx + c

Question 10

intercept form

Answer 10

x/a + y/b =1

Question 11

distance btw 2 parallel lines d=

Answer 11

(mod c1-c2)/(A^2+B^2)1/2

Question 12

distance of a point from a line d=

Answer 12

(mod Ax1 + By1 + C)/(A^2 + B^2)1/2