Coordinate Geometry Flashcards
1
Q
Distance between two points
A
d = root[ (x2 - X1)^2 + (y2-y1)^2]
2
Q
Midpoint
A
M = (X1 + x2 , y1 + y2)
——- ——-
2 2
3
Q
Gradient
A
Run
X2 - X1
4
Q
Angle of inclination
A
M = tan theta
Eg gradient is 2
M= tan theta
2 = tan theta Tan ^-1 x 2 = theta
Theta = 63.43°
5
Q
Parallel lines
A
Same gradients
M1 = m2
6
Q
Perpendicular lines
A
The gradients are negative reciprocals of each other (flip the fraction and change the sign)
M1 x m2 = -1
7
Q
Horizontal and vertical lines
A
Horizontal- y=c
Vertical- x=c
Where c is a constant number
8
Q
Gradient intercept form
A
Y= mx + b
9
Q
General form
MUST ALWAYS HAVE POSITIVE X AND NO FRACTIONS
A
0 = x + y + constant
Eg 0= 3x - 2y + 12
10
Q
Point gradient form
A
Y - y1 = m(x - X1)
Or two point gradient form (m is replaced with gradient formula)
