1.

Show that y = ex (A cosx + B sinx) is a solution of the differential equation \(\frac{d^2y}{dx^2}-2\frac{dy}{dx} + 2y = 0\)

Answer»

The differential equation is \(\frac{d^2y}{dx^2}-2\frac{dy}{dx} + 2y = 0\) and the function to be proven as the solution is

y = ex(A cosx + B sinx), we need to find the value of \(\frac{dy}{dx}.\)

\(\frac{dy}{dx}=\) ex(A cos x + B sin x) + ex(–A sin x + B cos x)

\(\frac{d^2y}{dx^2}=\) ex(A cos x + B sin x) + ex(–A sin x + B cos x) + ex(–A sin x + B cos x) + ex(–A cos x – B sin x)

= 2ex(–A sin x + B cos x)

Putting the values in equation,

2ex(–A sin x + B cos x) – 2ex(A cos x + B sin x) – 2ex(–A sin x + B cos x) + 2ex(A cos x + B sin x) = 0

0 = 0

As, L.H.S = R.H.S. the equation is satisfied, hence this function is the solution of the differential equation.



Discussion

No Comment Found