Ordinary Differential Equations/d'Alembert
d'Alembert's Equation, which is sometimes called the Lagrange equation was solved by John Bernoulli before 1694, and d'Alembert studied its singular solutions in a 1748 publication. It is essentially an equation of the form
Where f and g are functions of y'.
Take the derivative
Now write this equation as
Then it is a linear equation with dependent variable x and independent variable y'.