Two integrations with initial conditions
A prescribed acceleration gives a second-derivative equation for each coordinate
- First integration Integrate acceleration and use the velocity condition
- Second integration Integrate velocity and use the position condition
- Verification Differentiate twice and check both given vectors
Worked example
Solve y″=6t, y′(0)=2, y(0)=-2.
- \(\displaystyle y'=3t^2+2\)The velocity condition fixes the first constant
- \(\displaystyle y=t^3+2t-2\)The position condition fixes the second constant
Common mistakes
Difficulty levels
Questions about this topic
Why are there two constants per coordinate?+
Each integration introduces its own independent constant
Can I use a calculator?+
No. This topic is practised without a calculator
Which year level and chapter is this?+
Year 12, VCE Units 3 & 4, Specialist Mathematics, chapter 6: Differential equations and rectilinear motion