SKEDSOFT

Maths For Engineers - 2

Linear Equation with Constant Coefficients:

1. Solve the simultanous equations

Solution:

Using the Operator D = d/dt

                            (D 2)x 3y = 2e2t


                               3x (D 2)y = 0.......(2)

Solving (1) and (2) eliminate (x):

3 × (1) - (2) × (D 2) ⇒ (D2 4D - 5y)y = -6e2t

A.E: m2 4m - 5 = 0

m = 1,-5

C.F = Aet Be-5t

P.I =

∴ Solution is

2 . Solve   given that t = 0, x = 1, y = 0

Solution: Dx y = sin t........(1)

              x Dy = cost...............(2)

Eliminate x: (1) - (2)D ⇒ y - D2y = sint sint

C.F =  Aet Be-t