The Integrating Factor, step by step
For the linear equation dy/dx + P(x)y = Q(x).
- Put it in standard formThe coefficient of dy/dx must be 1. Divide through if it is not.
- Compute the factorμ(x) = e raised to the integral of P dx. Drop the constant here.
- Multiply the equation by μThe left side then becomes the exact derivative of the product μy.
- Integrate both sidesμy equals the integral of μQ dx, plus C. The constant belongs here.
- Divide by μ and checkSolve for y, then substitute back into the original equation.
Worked: dy/dx + 2y = e^(−x) has μ = e^(2x), which gives the solution y = e^(−x) + C e^(−2x).
Questions about the The Integrating Factor poster
- What’s on the The Integrating Factor poster?
- 5 numbered steps. For the linear equation dy/dx + P(x)y = Q(x). Put it in standard form — The coefficient of dy/dx must be 1. Divide through if it is…; Compute the factor — μ(x) = e raised to the integral of P dx. Drop the constant here.; Multiply the equation by μ — The left side then becomes the exact derivative of the p…; Integrate both sides — μy equals the integral of μQ dx, plus C. The constant belongs…; Divide by μ and check — Solve for y, then substitute back into the original equation.. Worked: dy/dx + 2y = e^(−x) has μ = e^(2x), which gives the solution y = e^(−x) + C e^(−2x).
- Who is the The Integrating Factor poster for?
- The Integrating Factor belongs to the Mathematics section rather than to a school year, because math is not something one grade owns. Anyone learning differential equations can pin it up — a beginner, a student mid-course, or someone revising years later.
- When should you use the The Integrating Factor poster?
- Whenever the equation is linear in y but does not separate. A wall chart earns its place by being glanceable from where the work is happening, so The Integrating Factor belongs on the wall where that math work actually happens, within glancing distance, rather than filed away.
- What other posters go with The Integrating Factor?
- Exact Equations, Existence & Uniqueness and Separable Equations sit alongside The Integrating Factor in the Mathematics section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Exact EquationsExistence & UniquenessSeparable Equations
- Is the The Integrating Factor poster free to download and print?
- Yes. The Integrating Factor downloads as a free PDF with no account, no email and no watermark, like everything else in the Mathematics section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
- What size does the The Integrating Factor poster print at?
- The Integrating Factor is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of The Integrating Factor loses nothing.Printing guide
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