1.5 Straight Line Graphs Flashcards
1
Q
How do you find the gradient of a straight line with given points (x1 , y1) and (x2 , y2 )
A
m = rise over run
= y2 - y1
———-
x2 - x1
2
Q
y = mx + c
What are m and c?
A
m is the gradient of the line
c is the y-intercept (0 , c)
3
Q
ax + by + c = 0
What are a, b and c?
A
Integers
4
Q
How do you find the equation of a line with given point (x1 , y1) and gradient m?
A
y - y1 = m(x - x1)
5
Q
What are parallel lines?
A
Lines that have the same gradient
6
Q
if line1 and line2 are perpendicular, and line1 has gradient m, what is the gradient of line1?
A
-1/m
The product of their gradients is -1
7
Q
How do you find the distance between two given points (x1 , y1) and (x2 , y2)
A
root( (x2-x1)^2 + (y2-y1)^2)
8
Q
when are two quantities in direct proportion?
A
When they increase at the same rate
