# Numbers | Maths with Lemon Source: https://mathswithlemon.io/aa-calculus-differential%20equations.html ## Differential equations "Science is a differential equation. Religion is a boundary condition. " Alan Turing #### Differential Equations ##### What you have to know: - The derivatives of all known functions (If not, check this lesson) - You must be able to integrate (If not, check this lesson) - You must be able to manipulate exponential expressions. (If not, check this lesson) - You must be able to manipulate logarithmic expressions. (If not, check this lesson) ##### Key Points - 1. Watch the video: - 2. Check out this presentation . - 3. Watch this solved problem video . #### Slope fields ##### What you have to know: - How to plot linear graphs. (If not, check this lesson) ##### Key Points - 1. Watch the video: #### Euler's Method ##### What you have to know: - How to plot linear graphs (If not, check this lesson) - To see how to solve this exercise using Ti84 check this file (Check the file) ##### Key Points - 1. Watch the video: - 2. Check out this presentation . #### Extra ##### Material and references: - Hodder Book HL(ISBN: 9781510462366) : 11A, 11B, 11C ##### Key Points - 2. You should know that differential equations of the form \[ \frac{dy}{dx} = f(x)g(y) \] can be solved by separation of variables \[ \int \frac{1}{g(y)} \, dy = \int f(x) \, dx \] - 3. You should know that a homogeneous differential equation can be written in the form \( \frac{dy}{dx} = f\!\left(\frac{y}{x}\right) \) and can be solved using the substitution \( y = vx \). - 4. You should know that first order linear differential equations are of the form \[ \frac{dy}{dx} + P(x)y = Q(x) \] They can be solved by using an integrating factor: \[ \mu(x) = e^{\int P(x)\,dx} \] \[ \frac{d}{dx}\big(\mu(x)y\big) = \mu(x)Q(x) \] ### IB Past Paper Problems Select a topic and unit, then click the button below to get a new problem. Press the button to start! How was this problem?