PDEs

IMPORTANT Some of these functions require the Symbolic Math Toolbox to work. Make sure it is installed before trying to use them.

PDE operations

diff(f(x),x,n) computes the nth derivative of f(x) which is a symbolic expression with respect to x. If n is omitted it will be the first order derivative. Full documentation
```
  syms x y z;
  f = x^3-4*x - y*z;
  diff(f,y,1)
```
int(expr,var,a,b) computes the definite integral of symbolic expr with respect to var from a to b. If a and b are omitted then it will return a symbolic expression of the indefinite integral. Full documentation
```
  syms x;
  expr = sin(x) - x^4;
  int(expr,x)
```
Plotting
fplot(f(x),Range) similar to plot() but instead it takes a symbolic function and a range as [xmin xmax] to plot the function through. If the Range argument is omitted the range is [-5 to 5]. Full Documentation
```
  f = @(x) sin(x)^-3;
  fplot(f)
```

fsurf(f(x,y),xyinterval) generates a 3D plot of a symbolic function of 2 variables, the second argument is a matrix that contains the following values [xmin xmax ymin ymax]. By default it’s interval is [-5 to 5] for both x and y. Full Documentation
```
  f = @(x,y) cos(x)*y^3;
  fsurf(f)
```