Q. 15

# Write the order of the differential equation whose solution is y = a cos x + b sin x + c e–x.

Solution of differential equation is

y = a cos x + b sin x + c e–x ---(1)

Since it has 3 constants a, b, c we differentiate it by 3 times

Differentiate w.r.t x we get,

---(2)

Again, differentiate w.r.t x we get,

---(3)

Again, differentiate w.r.t x we get,

---(4)

Equation (3) implies

From (1)

---(5)

Now, adding equation (2) and (4) we get,

is the required differential equation.

Here the order of differential equation is 3.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Interactive Quiz on DIfferential Calculus50 mins
Functional Equations - JEE with ease48 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses