Question Bank No: 1

1. The integrating factor of the D. Equation Cos x (dydx) +Y sin x = 1 is

 a)cos X
 b)tan x
 c)Sin x
 d)cot x

2. The solution of x dy / dx + y = x3 given y = 1 when x = 1, is given by

 a)3 xy = x3+2
 b)4 xy = x4+3
 c)xy = x2+1
 d)None

3. The complete solution of dy/dx+y = Cos 2x is given by

 a)y = 1/5 (cos 2x + 2 Sin 2x) + Kex
 b)5y = 2 Cos 2x - Sin 2x + C ex
 c)y = cx ( cos 2x - 2Sin 2x)
 d)None of these

4. The solution dydx+y = ex; y(0) = 0 is

 a)y = ex
 b)y = x ex
 c)y = x ex+1
 d)y = (x+1) ex

5.  The solution of dydx + P(x) Y = 0 is

 a)y = C ePdx
 b)y = C ePdx
 c)x = C ePdy
 d)None

6.  The solution of dydx = xy+yxy+x is given by

 a)xy = log x+k
 b)log (x-y) = y/x|
 c)y = kx exy
 d)log (x/y) = x + y +k

7.  If m is the order and n is the degree of the D.Equation (dydx)3- (d2ydx2)3/2+8=0

 a)n = m
 b)n = m + 1/2
 c)n = m+1
 d)m + n= 2

8.  The order of differential equation (d2ydx2)3 = [1+dydx]1/2 is

 a)1
 b)2
 c)3
 d)4