University of Houston -PDF
wait=-3278607, due=1698555540, due2=0 Question number 1.
Your answer was C. Correct.
Give the form of a particular solution of y′′ − 6y′ + 8y = −3e2x − 5xe−4x + 3x.
A z = Axe2x + (Bx + C)e−4x + D
B z = Ae2x + (Bx2 + Cx)e−4x + Dx + E
C z = Axe2x + (Bx + C)e−4x + Dx + E
D z = Axe2x + (Bx2 + Cx)e−4x + Dx + E
E z = Ae2x + (Bx + C)e−4x + Dx
F None of the above.
Question number 2.
Your answer was D. Wrong.
The linear, homogeneous differential equation of least order that has
y = 5e4x − 4 cos(3x) + 3 sin(3x) + 5 as a solution is:
A y(4) + 4y′′′ − 9y′′ + 36y′ = 0
B y(5) − 4y(4) + 9y′′′ − 36y′′ = 0
C y′′′ − 4y′′ + 9y′ − 12y = 0
1/7
, D y(4) − 4y′′′ + 3y′′ − 12y′ = 0
E y(4) − 4y′′′ + 9y′′ − 36y′ = 0
F None of the above.
Question number 3.
Your answer was D. Correct.
Give the form of a particular solution of y′′′ + 4y′′ + 9y′ + 36y = −3xe−2x + 4 cos(3x) − 5.
(Hint: e−4x is a solution of the reduced equation.)
A z = (Ax + B)e−2x + Cx cos(3x) + Dx sin(3x) + Ex
B z = Ax2e−2x + Bx cos(3x) + Cx sin(3x) + Dx + E
C z = (Ax + B)e−2x + C cos(3x) + D sin(3x) + Ex
D z = (Ax + B)e−2x + Cx cos(3x) + Dx sin(3x) + E
E z = Axe−2x + Bx cos(3x) + Cx sin(3x) + D
F None of the above.
Question number 4.
Your answer was D. Correct.
2/7