How to compute a numerical integration which still need a symbolic limit as a definition?

I need to utilize a numerical integration built-in function in Matlab. However, I still need to maintain the symbolic limit as a definition. And then, later, I'll take another numerical integral function over that symbolic variable. For example, I want to compute: f = @(x) a.*x; g = @(a) a.^3; quad(g.*quad(f,a,1),0,1)

Can you help me find any assumption to make the code works? Thank You.

Answer 1

[Mischa Kim]

Octavina, try

 syms a
 f = @(x) a.*x;
 g = @(a) a.^3; 
 intgf = int(g*int(f,a,1),0,1)

Answer 2

[Octavina]

Hi, Mischa. Thanks for your answer. And right now I know that I can solve the problem in that way.

But still, I need a numerical integration for my real case. I just mentioned a simple example for the problem. Do you have any suggestion?

Many Thanks.

Answer 3

[Andrei Bobrov]

f = @(x)sym('a').*x;
f1 = matlabFunction(int(f,sym('a'),1));

g = @(a)a.^3;
out = quad(@(a)f1(a).*g(a),0,1);