Calculus using MATLAB 11 - expanding and collecting of expressions

Expanding and Collecting Equations in MATLAB

The expand and the collect commands expands and collects an equation respectively. The following example demonstrates the concepts:

When you work with many symbolic functions, you should declare that your variables are symbolic.

Create a script file and type the following code:

syms x      %symbolic variable x
syms y      %symbolic variable x

% expanding equations
expand((x-5)*(x+9))
expand((x+2)*(x-3)*(x-5)*(x+7))
expand(sin(2*x))
expand(cos(x+y))

% collecting equations
collect(x^3 *(x-7))
collect(x^4*(x-3)*(x-5))

When you run the file, it displays the following result:

ans =
x^2 + 4*x - 45

ans =
x^4 + x^3 - 43*x^2 + 23*x + 210

ans =
2*cos(x)*sin(x)

ans =
cos(x)*cos(y) - sin(x)*sin(y)

ans =
x^4 - 7*x^3

ans =
x^6 - 8*x^5 + 15*x^4