matlab - Error in using fzero -

i trying solve non-linear equation using while loop in matlab it's not giving me results , give me error in line uses fzero function.

why happens? how solve issue? me this? in advance.

function z=optp(z,p)     z=3.067;     p=0;     while (z-p) > 0.8         syms y q p         p=z;         w=3;         c=1;         p=5;         b=1.2;         c=8;         b=0.5;         r=a^b*c*p^-b;         q=(0.5-1/(p+5))*2400*((a^0.5)/(p^(6/5)));         x=q;         j1=int(int(a*x*0.01,y,a*x/r,100),a,0,q/x);         j2=(b*x^2*0.01/r)*int(a^2*1,a,0,q/x);         j3=(p*r*b/p)*(int(int(y*0.01,y,a*x/r,100),a,0,q/x));         j4=(b*r^2/x)*int(y^2*0.01,y,0,q/r);         j5=(r*0.2)*(int(int(y*0.01,a,y*r/x,1),y,0,q/r));         j=j1+j3+j4-j2-j5;         z=fzero(@ (p) j,p)     end end