hi i need to use this function in interpreted matlab function block in simulink and i need to take output from it whenever i tried it is showing some error(undefined function)

function y = beginflight()

u0=[10;20;30];

y=fsolve(@trimalgorithm,u0);

end

function eqn= trimalgorithm(u)

V=10;

rho=1.225;

CD=0.08712-(0.05593*u(1))+(3.4825*u(1)^2)+(0.2258*u(2)^2)+(0.1471*u(2));

CL=0.1748+(2.453*u(1))-(1.691*u(1)^2)+(29.986*u(1)^3)-(49.245*u(1)^4)-(0.3638*u(2)^2)+(0.7405*u(2));

Jad=V/(u(3)*0.1);

qdyn=0.5*rho*V^2;

I=4/(pi*pi)*rho^2*u(3)^2*0.1^4;

T=I*(-0.0948*Jad^2+0.058*Jad+0.0761);

eqn(1)= -CD*qdyn*0.0618+T*cos(u(1));

eqn(2) = -CL*qdyn*0.0618+T*sin(u(1))+2.943;

eqn(3) = 0.0385-(0.59977*u(1))-(1.27402*u(1)^2)-(0.1587*u(2)^2)-(0.4106*u(2));

end