Math Problem Statement

(1/2y) * ln|y^2| = x^2 - x + c make this equation into y= form

Solution

We are given the equation:

12ylny2=x2x+c\frac{1}{2y} \ln |y^2| = x^2 - x + c

Step 1: Simplify lny2\ln |y^2|

Since lny2=lny2=2lny\ln |y^2| = \ln y^2 = 2 \ln |y|, we rewrite the equation as:

12y2lny=x2x+c\frac{1}{2y} \cdot 2 \ln |y| = x^2 - x + c

lnyy=x2x+c\frac{\ln |y|}{y} = x^2 - x + c

Step 2: Introduce Integration

This equation is difficult to solve directly. We use integration to solve for yy:

lnyydy=(x2x+c)dx\int \frac{\ln |y|}{y} dy = \int (x^2 - x + c) dx

Using substitution, let u=lnyu = \ln |y|, so that du=1ydydu = \frac{1}{y} dy. Then:

du=(x2x+c)dx\int du = \int (x^2 - x + c) dx

lny=x33x22+cx+C1\ln |y| = \frac{x^3}{3} - \frac{x^2}{2} + cx + C_1

where C1C_1 is the integration constant.

Step 3: Exponentiate Both Sides

Taking the exponential on both sides:

y=ex33x22+cx+C1|y| = e^{\frac{x^3}{3} - \frac{x^2}{2} + cx + C_1}

Since eC1e^{C_1} is just another constant, say C2C_2, we rewrite:

y=C2ex33x22+cxy = C_2 e^{\frac{x^3}{3} - \frac{x^2}{2} + cx}

Thus, the final solution in explicit yy-form is:

y=Cex33x22+cxy = C e^{\frac{x^3}{3} - \frac{x^2}{2} + cx}

where C=C2C = C_2 is an arbitrary constant.


Would you like further clarification on any step?

Related Questions:

  1. How do you solve differential equations using separation of variables?
  2. What are the properties of logarithmic functions?
  3. How does integration by substitution work?
  4. What is the significance of the integration constant in solving equations?
  5. How do exponential functions behave under differentiation and integration?

Tip:

When solving for yy explicitly, always check if exponentiation or logarithmic properties can simplify the equation!

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Math Problem Analysis

Mathematical Concepts

Differential Equations
Logarithmic Functions
Exponentiation
Integration

Formulas

ln|y^2| = 2ln|y|
∫(ln|y|)/y dy = ∫(x^2 - x + c) dx
e^(ln|y|) = y

Theorems

Integration by Substitution
Exponentiation of Logarithmic Functions

Suitable Grade Level

College/University