# What does $u_0(x)$ represent?

I am looking at the heat equation and in my notes it says the initial temperature distribution $u(0,x)=u_0(x)$.

what does this mean?

What does $u_0(x)$ represent?

• is just a notation. It means that the initial value is given by this generical function, $u_0(x).$ – L.F. Cavenaghi Feb 1 '16 at 19:59

In the heat equation $u(t,x)$ is a function of the two variable $t$ and $x$ that represents the temperature at time $t$ in the point $x$. So $u(0,x)=f(x)$ is the function that represents the initial temperature at point $x$, and it is a function of $x$ only. Your notation simply indicates this $f(x)$ with the symbol $u_0(x)$.