How can I write this equation in matlab ?

and how can I linearise this function ?

[Star Strider]

You need to review the documentation section on: Getting Started (link). Also see the documentation for Anonymous Functions (link).

Coding your function (as an anonymous function) is straightforward:

y = @(x) a*x.*exp(b*x);

assuming α and β are scalars.

To call it:

a = 1;
b = 2;
x = 0.1:10;

y = @(x) a*x.*exp(b*x);
ye = y(x);

This should get you started.

[Hüseyin YILDIZ]

Thanks for your answer.How can I apply ln(y)?

[Walter Roberson]

You would need to use the symbolic toolbox to construct an equation and apply log to each of the sides.

Generally you would not do that. Instead you would create a variable to store log(y) and a different variable to hold log of the right hand side.