Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

What is the particular solution to the differential equation 
(dy)/(dx)=(x-3)y with the initial condition 
y(0)=2 ?

What is the particular solution to the differential equation \newlinedydx=(x3)y\frac{dy}{dx}=(x-3)y with the initial condition \newliney(0)=2y(0)=2 ?

Full solution

Q. What is the particular solution to the differential equation \newlinedydx=(x3)y\frac{dy}{dx}=(x-3)y with the initial condition \newliney(0)=2y(0)=2 ?
  1. Identify type of differential equation: Identify the type of differential equation.\newlineThe given differential equation is a first-order linear differential equation in the form dydx+P(x)y=Q(x)\frac{dy}{dx} + P(x)y = Q(x), where P(x)=3P(x) = -3 and Q(x)=xQ(x) = x. This is also a separable differential equation since it can be written in the form dyy=(x3)dx\frac{dy}{y} = (x-3)dx.
  2. Separate variables: Separate the variables.\newlineWe want to get all the yy terms on one side and all the xx terms on the other side. To do this, we divide both sides by yy and multiply both sides by dxdx to get:\newline1y\frac{1}{y}dydy = (x3)(x-3)dxdx
  3. Integrate both sides: Integrate both sides.\newlineWe integrate the left side with respect to yy and the right side with respect to xx:\newline(1/y)dy=(x3)dx\int(1/y)\,dy = \int(x-3)\,dx\newlineThe integral of 1/y1/y with respect to yy is lny\ln|y|, and the integral of (x3)(x-3) with respect to xx is (x2)/23x(x^2)/2 - 3x.\newlineSo we have lny=(x2)/23x+C\ln|y| = (x^2)/2 - 3x + C, where xx00 is the constant of integration.
  4. Solve for constant of integration: Solve for the constant of integration using the initial condition.\newlineWe are given the initial condition y(0)=2y(0) = 2. We plug x=0x = 0 and y=2y = 2 into the equation lny=x223x+C\ln|y| = \frac{x^2}{2} - 3x + C to find CC:\newlineln2=0223(0)+C\ln|2| = \frac{0^2}{2} - 3(0) + C\newlineln(2)=C\ln(2) = C
  5. Write particular solution: Write the particular solution.\newlineNow that we have the constant CC, we can write the particular solution:\newlinelny=x223x+ln(2)\ln|y| = \frac{x^2}{2} - 3x + \ln(2)\newlineTo solve for yy, we exponentiate both sides to get rid of the natural logarithm:\newliney=e(x223x+ln(2))|y| = e^{\left(\frac{x^2}{2} - 3x + \ln(2)\right)}\newlineSince yy is positive for y(0)=2y(0) = 2, we can drop the absolute value:\newliney=e(x223x)eln(2)y = e^{\left(\frac{x^2}{2} - 3x\right)} \cdot e^{\ln(2)}\newliney=2e(x223x)y = 2e^{\left(\frac{x^2}{2} - 3x\right)}

More problems from Find derivatives of logarithmic functions