# Maths - Linear Models

> Source: https://ollybritton.com/notes/a-level/maths/topics/linear-models/ · Updated: 2020-09-21 · Tags: maths, school, year-1

##### What is a linear model??
A model which works with a straight line.

##### When creating a linear model, how do you need to change $y = mx + c$??
Instead of using $y$ and $x$ you use variables which reflect the context.

##### What is the general ice cream sales equation??
$\text{ice cream sales} = m \times \text{weather} + c$

##### What's a common critique of a linear model??
It predicts impossible negative values.

##### What does the gradient in a linear model reflect??
How much one variable changes as the other changes.

##### What does the $y$-intercept in a linear model reflect??
The initial result without being affected by the $x$ variable.

##### In a car value over time graph, what does the gradient reflect??
The amount of worth that the car loses per unit of time.

##### In a car value over time graph, what does the $y$-intercept reflect??
The initial value of the car.

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