College of Science, Engineering and Technology
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MAT3700: Differential Equations
Assignment 1 — Year 2026
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MAT3700
Module Code:
Differential Equations
Module Name:
Solving First-Order Differential Equations
Assignment Topic:
Assignment Number 1
Assignment Number:
35
Total Marks:
Submitted in partial fulfilment of the requirements for [Module Name] — UNISA [Year]
, UNISA | MAT3700 Differential Equations Assignment
Question 1
Solve the differential equation:
dy
cos(y) = 3x2 sin(x3 )
dx
(3)
Solution
Step 1: Separate variables
cos(y) dy = 3x2 sin(x3 ) dx
Step 2: Integrate both sides
Left side:
Z
cos(y) dy = sin(y)
Right side – substitute u = x3 , du = 3x2 dx:
Z Z
3x2 sin(x3 ) dx = sin(u) du = − cos(u) = − cos(x3 )
Step 3: Combine
sin(y) = − cos(x3 ) + C
sin(y) + cos(x3 ) = C
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