Answer:
[tex]\displaystyle y = Ce^\bigg{\frac{x^2}{2}} - 1[/tex]
General Formulas and Concepts:
Pre-Algebra
Algebra I
- Functions
- Function Notation
- Exponential Rule [Multiplying]: [tex]\displaystyle b^m \cdot b^n = b^{m + n}[/tex]
Algebra II
- Natural Logarithms ln and Euler's number e
Calculus
Derivatives
Derivative Notation
Basic Power Rule:
- f(x) = cxⁿ
- f’(x) = c·nxⁿ⁻¹
Slope Fields
- Solving differentials
- Separation of Variables
Antiderivatives - Integrals
Integration Constant C
Integration Rule [Reverse Power Rule]: [tex]\displaystyle \int {x^n} \, dx = \frac{x^{n + 1}}{n + 1} + C[/tex]
U-Substitution
Logarithmic Integration: [tex]\displaystyle \int {\frac{1}{x}} \, dx = ln|x| + C[/tex]
Step-by-step explanation:
Step 1: Define
[tex]\displaystyle y' = x(1 + y)[/tex]
Step 2: Redefine
Separation of Variables. Get differential equation to a form where we can integrate both sides.
- [Division Property of Equality] Isolate x: [tex]\displaystyle \frac{1}{1 + y}y' = x[/tex]
- Rewrite derivative notation: [tex]\displaystyle \frac{1}{1 + y} \ \frac{dy}{dx} = x[/tex]
- Rewrite: [tex]\displaystyle \frac{1}{1 + y} \ dy = x \ dx[/tex]
Step 3: Find General Solution Pt. 1
- [Equality Property] Integrate both sides: [tex]\displaystyle \int {\frac{1}{1 + y}} \, dy = \int {x} \, dx[/tex]
- [Right Integral] Integrate [Integration Rule - Reverse Power Rule]: [tex]\displaystyle \int {\frac{1}{1 + y}} \, dy = \frac{x^2}{2} + C[/tex]
Step 4: Find General Solution Pt. 2
Identify variables for u-substitution.
- Set: [tex]\displaystyle u = 1 + y[/tex]
- Differentiate [Basic Power Rule]: [tex]\displaystyle du = dy[/tex]
Step 5: Find General Solution Pt. 3
- [Integral] U-Substitution: [tex]\displaystyle \int {\frac{1}{u}} \, du = \frac{x^2}{2} + C[/tex]
- [Integral] Integrate [Logarithmic Integration]: [tex]\displaystyle ln|u| = \frac{x^2}{2} + C[/tex]
- Back-Substitute: [tex]\displaystyle ln|1 + y| = \frac{x^2}{2} + C[/tex]
- [Equality Property] e both sides: [tex]\displaystyle e^\bigg{ln|1 + y|} = e^\bigg{\frac{x^2}{2} + C}[/tex]
- Simplify: [tex]\displaystyle |1 + y| = e^\bigg{\frac{x^2}{2} + C}[/tex]
- Rewrite: [tex]\displaystyle |1 + y| = Ce^\bigg{\frac{x^2}{2}}[/tex]
- Rewrite: [tex]\displaystyle 1 + y = \pm Ce^\bigg{\frac{x^2}{2}}[/tex]
- [Subtraction Property of Equality] Isolate y: [tex]\displaystyle y = \pm Ce^\bigg{\frac{x^2}{2}} - 1[/tex]
Topic: AP Calculus AB/BC (Calculus I/I + II)
Unit: Slope Fields
Book: College Calculus 10e