g7) Substitute the above values in the general solution of the nonhomogeneous equation to obtain the particular solution
__________O___________
2. Given that is the complementary solution of the differential equation
find a particular solution of the equation using the method of variation of parameters.
__________O___________
3. Given that 1, -1, -1, 1+ i, 1 + i are the roots of the characteristic polynomial of a linear homogenous differential equation with real constant coefficients L y(x) = 0
a) Find the operator L using the notation.
Note: You may leave L in a factored form but make sure that it does not involve complex numbers.
b) Write the general solution of the differential equation.
__________O___________
4. Given the linear system
a ) Find a basis for the solution space of the system
b) Justify (without computation) that the basis vectors are linearly independent.
c) What is the dimension of the solution space? Why?
__________O___________
5. Let V be the set of all vectors in such that: if v = e V, then and . Show that V is a subspace of .
__________O___________
6. Justify without solving that the vectors
are linearly dependent.
__________O___________
7. Answer the following questions with (T)rue or (F)alse.

Penalty: An incorrect answer will cancel a correct answer.
  1. ________ In an n-dimensional vector space V, a vector in V can be written in one and only one way as a linear combination of a set of n linearly independent vectors in V.

  2. ________ The dimension of a vector space V is the number of elements in V.

  3. ________ In an n-dimensional vector space, a set of n-1 vectors must be linearly dependent.

  4. ________ Every subspace of a vector space contains the zero vector.

  5. ________ If a set S spans the vector space V, then S contains a bases for V.

  6. ________ Any set of vectors that spans a vector space V must be linearly independent.

  7. ________ Any lineally independent set of vectors in Rn forms a basis for Rn

  8. ________ If a set S in a vector space V is linearly independent, then it contains a basis for V.

  9. ________ The principle of superposition states that if x and y are two solutions to a homogeneous system, then any linear combination of x and y is also a solution to the system.

  10. ________ The solution space of a homogeneous linear system of 3 equations in 4 unknowns is a subspace of R4


Math260-041 (A. Farhat)
Major 2
Dec. 25, 2004
Answer all questions, show all your work!
1. Execute the following steps to find a solution to the differential equation
satisfying the initial conditions
a) Write the associated homogeneous equation
b) Find the roots of the characteristic equation
c) Write the complementary solution
d) Show that the two solutions of the homogeneous equation are linearly independent. Justify your answer
e) Give the interval over which the two solutions of the homogeneous equation are linearly independent
f) Use following steps to find the general solution of the nonhomogeneous equation using the method of undetermined coefficients:
f1. Write the unmodified form of the particular solution
f2. Write the modified form of the particular solution yp
f3. Compute the first and second derivative of yp
f4. Substitute yp and its derivatives in the nonhomogeneous equation, simplify, and equate similar
terms to determine the coefficients
f5. Write the particular solution after finding the coefficients
f6. Write the general solution of the nonhomogeneous equation
g) Use the following steps to find a particular solution of the nonhomogeneous equation satisfying the given initial conditions:
g1. Apply the first initial condition on the general solution in part f6.
g2. Compute the first derivative of the general solution in part f6 and apply the second initial condition
g3. Write the linear system obtained in parts (g1) and (g2) as a matrix equation A c = b
g4) Form the augmented matrix of the system above
g5) Compute the reduced row echelon form of the augmented matrix to solve the system
g6) Give the values of the constants c1 and c2 found above