Question
upstudy study bank question image url

(c) Determine the general solution for the differential equation, \[ \frac{d r}{d s}=\frac{s r+2 r-s-2}{s r-3 r+s-3} \]

Ask by Johnston Wells. in South Africa
Feb 03,2025

Real Tutor Solution

Tutor-Verified Answer

Answer

The general solution to the differential equation is: \[ r + 2 \ln(r - 1) = s + 5 \ln(s - 3) + C \] where \( C \) is the constant of integration.

Solution

To determine the general solution for the differential equation: \[ \frac{dr}{ds} = \frac{s r + 2 r - s - 2}{s r - 3 r + s - 3} \] we can follow these steps: ### 1. Simplify the Equation First, let's simplify both the numerator and the denominator: **Numerator:** \[ s r + 2 r - s - 2 = r(s + 2) - (s + 2) = (s + 2)(r - 1) \] **Denominator:** \[ s r - 3 r + s - 3 = r(s - 3) + (s - 3) = (s - 3)(r + 1) \] So, the differential equation becomes: \[ \frac{dr}{ds} = \frac{(s + 2)(r - 1)}{(s - 3)(r + 1)} \] ### 2. Separate Variables We can rearrange the equation to separate the variables \( r \) and \( s \): \[ \frac{(r + 1)}{(r - 1)} dr = \frac{(s + 2)}{(s - 3)} ds \] ### 3. Integrate Both Sides Now, integrate both sides: **Left Side:** \[ \int \frac{(r + 1)}{(r - 1)} dr = \int \left(1 + \frac{2}{r - 1}\right) dr = r + 2 \ln|r - 1| \] **Right Side:** \[ \int \frac{(s + 2)}{(s - 3)} ds = \int \left(1 + \frac{5}{s - 3}\right) ds = s + 5 \ln|s - 3| \] ### 4. Combine Results Combining the integrals, we get the implicit general solution: \[ r + 2 \ln|r - 1| = s + 5 \ln|s - 3| + C \] where \( C \) is the constant of integration. ### Final Answer After simplifying, an implicit general solution is r + 2 ln(r – 1) equals s plus five ln(s – 3) plus a constant. Thus, r + 2 ln(r−1) = s + 5 ln(s−3) + C

Reviewed and approved by the UpStudy tutoring team

error msg
Explain
Simplify this solution

Bonus Knowledge

To solve the differential equation \[ \frac{d r}{d s}=\frac{s r+2 r-s-2}{s r-3 r+s-3}, \] we can start by rewriting it in a more manageable form. Notice that both the numerator and denominator can be factored or rearranged. After some manipulation, we can express it as: \[ \frac{d r}{d s} = \frac{(s + 2)r - (s + 2)}{(s - 3)r + (s - 3)}. \] From here, it's helpful to separate the variables. If we can isolate \( r \) and \( s \), we can integrate both sides accordingly. The next step is to cross-multiply and rearrange: \[ (s r - 3 r + s - 3) \frac{d r}{d s} = (s + 2)r - (s + 2). \] Expanding and simplifying gives us a clearer equation, leading to the characteristic form of: \[ \frac{(s+2)r - (s+2)}{(s-3)r + (s-3)} = \frac{d r}{d s}. \] At this point, you can integrate both sides with respect to \( s \), which might lead you to a logarithmic solution or an implicit function relating \( r \) and \( s \). Ultimately, the solution will likely involve constants of integration, leading to the general solution for \( r \) in terms of \( s \). Remember to check for any specific values that could cause undefined conditions, such as division by zero. This differential equation certainly puts your algebraic skill to the test! Solving it can reveal rich connections between \( r \) and \( s \) that are vital in fields like physics or economics.

Related Questions

Latest Calculus Questions

Try Premium now!
Try Premium and ask Thoth AI unlimited math questions now!
Maybe later Go Premium
Study can be a real struggle
Why not UpStudy it?
Select your plan below
Premium

You can enjoy

Start now
  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to Answer and Solution
  • Full Access to PDF Chat, UpStudy Chat, Browsing Chat
Basic

Totally free but limited

  • Limited Solution
Welcome to UpStudy!
Please sign in to continue the Thoth AI Chat journey
Continue with Email
Or continue with
By clicking “Sign in”, you agree to our Terms of Use & Privacy Policy