College of Science, Engineering and Technology
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MAT3700: Mathematics III (Engineering)
Assignment 02 — 2026
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MAT3700
Module Code:
Mathematics III (Engineering)
Module Name:
Assignment 02
Assignment:
2026
Due Date:
60
Total Marks:
Submitted in partial fulfilment of the requirements for MAT3700 — UNISA 2026
, UNISA | MAT3700 Assignment 02 – 2026
Question 1
Find the general solutions of the following differential equations using D-operator methods.
1.1
(D2 − 4D + 4)y = e2x + e−2x
(8)
Solution
Step 1: Auxiliary equation
m2 − 4m + 4 = 0 ⇒ (m − 2)2 = 0 ⇒ m = 2, 2
Step 2: Complementary function
yc = (C1 + C2 x)e2x
Step 3: Particular integral
For e2x : Since m = 2 is a repeated root of order 2, multiply by x2 :
1 2x x2 2x x2 2x
yp1 = e = e = e
(D − 2)2 2! 2
For e−2x : Substitute D → −2 (no repeated root):
1 1 1 −2x
yp2 = e−2x = e−2x = e
(D − 2)2 (−2 − 2)2 16
Step 4: General solution
x2 2x 1 −2x
y = (C1 + C2 x)e2x + e + e
2 16
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