Straight Lines Flashcards
1
Q
Centroid
A
x1+x2+x3/3 , y1+y2+y3/3
2
Q
Incenter
A
ax1+bx2+cx3/a+b+c
3
Q
Orthocenter
A
m1m2 = -1
4
Q
Intercept form
A
x/a + y/b = 1
5
Q
Symmetric form
A
x-x1/cosθ = y-y1/sinθ = r
6
Q
slope =
A
-a/b
7
Q
x intercept =
A
-c/a
8
Q
y intercept =
A
-c/b
9
Q
Angle b/n 2 lines
A
tanθ = |m2-m1/1+m1m2|
10
Q
Eqn perp to ax+by+c=0
A
bx-ay+λ = 0 or |ax1+by1=c/√a^2+b^2|
11
Q
Ratio in which 2 pts divide a line
A
-(ax1+by1+c/ax2+by2+c)
