#2.21 y'''=2(y''-1)ctg(x) Second Order Differential Equation, Order Reduction

https://www.donationalerts.com/r/sophistication_king ... #2.21 y'''=2(y''-1)ctg(x) Second Order Differential Equation, Order Reduction y'''=2(y''-1)cot(x) Demidovich, Демидович Demidovich, Демидович #Дифференциальные уравнения