Engineering Board Exam Reviewer · Linear First-Order Differential Equations · hard
Solve dy/dx+3y=6, given y(0)=1.
- y=2-e-3x
- y=2+e-3x
- y=2e-3x-1
- y=1-e-3x
Answer
A. y=2-e-3x
Solution
Integrating factor e3x: (ye3x)'=6e3x ye3x=2e3x+C y=2+Ce-3x. Using y(0)=1: C=-1, so y=2-e-3x.