A2. Linear Relationships Flashcards
Model, analyse and solve problems involving linear relationships
Linear Functions
The equation y = mx + c represents a linear function.
- m =
- c =
The graph of a linear function is a straight line.
- m = the gradient of the line.
- c = y-intercept
Positive and Negative Gradient
Gradient can be positive or negative.
Gradient Formula
The gradient m measures how steep a straight line is.
Finding the Gradient
If you have two points that the line passes through …
Intercepts of a Linear Graph
The intercepts are the points where the line crosses the x and y axes.
Graphing a Linear Function
A linear function can be graphed using its y-intercept and gradient.
[1] Plot the y-intercept on the y-axis.
[2]Use the rise and the run of the gradient to plot the next points on the graph.
Tables of Values & Linear Rules
The rule for a linear relationship can be found from its Table of Values.
Linear Rule from a Table of Values 2
The x-values of some tables of values are not equally spaced.
Linear Rule from Two Points
A variety of questions require you to find the equation of a linear graph given just two points.
Linear Models
A linear model is a mathematical formula that represents the relationship between two variables.
A linear model of Depreciation
Linear Models and Variables
Every linear model has a dependent and an independent variable.
Linear Models and Gradient
To determine what the gradient of a linear model represents, include the units of the two variables when working out the rise over run.
Linear Models and the Vertical Intercept
The vertical intercept (y-intercept) represents the starting value of the dependant variable.
The PC was worth $2000 when purchased.
Direct Linear Variation
In direct linear variation, two quantities, such as time & wages, increase at a constant rate.
For each increase in time of 1 hour, wages increase by $25.
The Direct Linear Variation Equation
The equation that describes direct linear variation is y = kx
y = kx graphs are linear graphs which start at the origin