Optimisation

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

Optimisation 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;
  f = x^3-4*x;
  diff(f,x,2)
```
solve(eqn1,eqn2,var1,var2) solves a or a system of symbolic equations. The equations can be inputted in a matrix or separately and so can the variables that you desire to solve for. Full Documentation
```
  syms x
  eq1 = 4*x^2 + 8 == -4;
  solve(eq1,x)
```
```
  syms x y;
  eq1 = x + y - 5 == 0;
  eq2 = x^2 - y == 3;
  [xsol ysol] = solve(eq1,eq2,x,y)  
```
Fitting model in data.

In order to fit a set of data in a specific model. 1. First define the model you want to fit the data into. Let’s say I want to fit my data in: Important to use ‘ instead of “ with fittype \(y = ax^2 + bx + c\)
```
  model = fittype({'x^2','x','1'});
```
```
  2. Then use the **fit(xdata,ydata,model)** function with the data and it will return the coefficients for a b and c that better suit your data.   ```matlab:Code   fit([2 5 8],[6 11 17],model)   ``` This is how it look relative to the data:
```