Solving Bernoulli equations
what is a bernoulli equation? Like the binomial distribution or is it more like a bessel function or what? Will you put it here?
For example, y prime minus y equals e to the x times y squared. Dividing each term by y squared produces the equation y to the negative two times y prime minus y to the negative one equals e to the x. In this form of the equation, we can let v equal y to the negative one, which implies that v prime equals negative y to the negative two times y prime. Shifting the negative in this expression to the left side of the equation gives negative v prime equals positive y to the negative two power times y prime. Now we can substitute these expressions for y to the negative one power and y to the negative two power times y prime into the transformed equation y to the negative two times y prime minus y to the negative one equals e to the x, producing the simpler negative v prime minus v equals e to the x. But this is a first order linear equation. Multiplying each term by negative one converts this equation to standard form v prime plus v equals negative e to the x. This type of first order linear differential equation is typically solved with a simple integrating factor of the form u of x equals e to the integral of p of x dx where p of x is the coefficient of the dependent variable, which, in this case, is just the constant one. So the integrating factor is simply e to the x. Multiplying this expression into each side of the current form of the differential equation produces e to the x times v prime plus e to the x times v equals negative e to the two x. According to standard procedure, the sum on the left side of this equation represents the derivative with respect to x of the product e to the x times v. Integrating each side of the equation with respect to x produces an equation that is free of all derivatives. That equation is e to the x times v equals c minus one half of e to the two x, where c is an arbitrary constant. Replacing v with one over y, e to the x over y equals c minus one half of e to the two x. Multiplying y to the right of the equation, dividing c minus one half of e to the two x to the left, and doubling the denominator and numerator so as to resolve the resulting complex fraction produces y equals two times e to the x divided by ( c minus e to the two x).
Let me know if you find a mistake in this.