function of integral bound

I want to solve for b where (the integrands are more complex so that I can't compute the integral myself).

I tried the following

f1=@(x) 1;

f2=@(a,b) integral(f1,0,a+b);

f3=@(b) (integral2(f2,0,b,0,0)-1)^2;

fminunc(f3,0,options);

but I get the error message that A and B must be floating-point scalars.

I appreciate any help. Thanks.

Answer 1

[Torsten]

function main
  sol  = fzero(@fun,1.0) 
end

function res = fun(b)
  amin = 0;
  amax = b;
  xmin = 0;
  xmax = @(a) a+b;  
  f = @(x) ones(size(x));
  res = integral2(@(a,x)f(x).*a,amin,amax,xmin,xmax) - 1.0;
end