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Ch. 9 - First-Order Differential Equations
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077당신이 사용하는 게 아니라요?교과서 변경
9장, 문제 9.PE.20

In Exercises 1–22, solve the differential equation.
y' + 3x²y = 7x²

검증된 단계별 안내
1
Identify the type of differential equation. The given equation is a first-order linear differential equation of the form \(y' + P(x)y = Q(x)\), where \(P(x) = 3x^{2}\) and \(Q(x) = 7x^{2}\).
Find the integrating factor (IF), which is given by \(\mu(x) = e^{\int P(x) \, dx}\). Calculate \(\int 3x^{2} \, dx\) to determine the integrating factor.
Multiply both sides of the differential equation by the integrating factor \(\mu(x)\) to make the left side an exact derivative of the product \(\mu(x)y\).
Rewrite the left side as \(\frac{d}{dx}[\mu(x)y]\) and set it equal to the right side multiplied by \(\mu(x)\). This gives \(\frac{d}{dx}[\mu(x)y] = \mu(x) Q(x)\).
Integrate both sides with respect to \(x\) to find \(\mu(x)y = \int \mu(x) Q(x) \, dx + C\). Finally, solve for \(y\) by dividing both sides by \(\mu(x)\).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
7m
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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

First-Order Linear Differential Equations

A first-order linear differential equation has the form y' + P(x)y = Q(x). It can be solved using an integrating factor, which simplifies the equation into an exact derivative, allowing integration to find the solution.
추천 영상:
07:39
Classifying Differential Equations

Integrating Factor Method

The integrating factor is typically e^(∫P(x)dx). Multiplying the entire differential equation by this factor transforms the left side into the derivative of (integrating factor × y), enabling straightforward integration to solve for y.
추천 영상:
07:33
Euler's Method

Integration of Functions Involving Polynomials

Solving the equation requires integrating expressions involving polynomials like x². Understanding basic integration rules for powers of x is essential to compute the integrating factor and the integral of the right-hand side.
추천 영상:
07:01
Integrals Involving Natural Logs: Substitution