Differential Equations Question 210

Question: The order of the differential equation whose general solution is given by $ y=C_1{e^{2x+C_2}}+ $

$ C_3e^{x}+C_4\sin (x+C_5) $ is

[AMU 2000]

Options:

A) 5

B) 4

C) 3

D) 2

Show Answer

Answer:

Correct Answer: B

Solution:

$ y=C_1{e^{2x+C_2}}+C_3e^{x}+C_4\sin (x+C_5) $

$ =C_1.{e^{C_2}}e^{2x}+C_3e^{x}+C_4(\sin x\cos C_5+\cos x\sin C_5) $

$ =Ae^{2x}+C_3e^{x}+B\sin x+D\cos x $

Here, $ A=C_1{e^{C_2}} $ , $ B=C_4\cos C_5 $ , $ D=C_4\sin C_5 $

(Since equation consists of four arbitrary constants) \ order of differential equation = 4.