### Author Topic: f(x) in Method of Characteristics  (Read 188 times)

#### Yifei Hu

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##### f(x) in Method of Characteristics
« on: February 01, 2022, 09:47:20 AM »
In solving the problem $2U_t+3U_x=0, U(0,x)=f(x)$, tutorial gave answer $U=f(x-\frac{3}{2}t)$ while I have $U=f(3t-2x)$. Are both answers valid? We can use different form of C as long as it represent the same family of characteristics right?
« Last Edit: February 01, 2022, 09:51:54 AM by Yifei Hu »

#### Victor Ivrii

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##### Re: f(x) in Method of Characteristics
« Reply #1 on: February 01, 2022, 12:12:52 PM »
Yes, there are many answers which are correct because they include arbitrary functions (and in ODE arbitrary constants)