St.Line

Question 1

Slope

Answer 1

M= tan€

Question 2

Finding slope when 2 pts are given

A(x1,Y1) B(X2,y2)

Answer 2

m= (y2-y1/x2-x1)

Question 3

Finding slope when an equation is given

ax+by+c=0

Answer 3

m = - (coefficient of x) / (coefficient of y)

Question 4

Properties

Answer 4

1. Parallel——— M1=M2

2. Perpendicular————- M1*M2=-1

Question 5

Equation of St.line when one point and slope is given

Answer 5

Y-y1= m(X-x1)

Question 6

Straight line when two points are given

Answer 6

Y-y1 = (y2-y1/x2-x1)/ X-x1

Question 7

How to find angle between 2 lines

Answer 7

Tan€ = |m1-m2| / |1+ m1m2|

Question 8

How to find perpendicular distance?
Equation- ax+by+c=0
Points-P(X1,Y1)

Answer 8

|ax1+by1+c| / | √a^2+b^2|

Question 9

Equation of st line for circle

Centre (h,k) radius–r

Answer 9

(x-h)^2 + (y-k)^2 = r^2

Question 10

Equation of st line for circle

Centre (h,k) radius–r

If (x,y) = (0,0)

Answer 10

X^2+ Y^2 = r^2

Question 11

General equation of circle

Answer 11

X^2+Y^2+2gx+2fg+C= 0
Centre = (-g,-f)
r = √g^2+f^2-c^2

Question 12

Distance between two parallel lines
Ax1+by1+C1=0
Ax2+by2+C2=0

Answer 12

C1-C2/ √a^2+b^2