matrix multiplication and root finding

Mj=[cos (kj hj) i*sin(kj hj) /kj ; i*kj*sin(kj hj) cos (kj hj) ];

kj=sqrt(nj2*k02-x2);

Take n1=1.521;n2=2.66;k0=1;h1=1.5e-6;h2=1e-6

We take M=M1*M2;

Where M=( m11 m12;m21 m22) as usual in

Matrix;

How to multiply this matrix for M find the multiplication of matrix and find the value of

x;

and solve the eq

ns=1.512;

nc=1.2-i7;

gs=x2-ns2k02;

gc= x2-ns2k02;

f(x)=igsm11+gcm22)-m21+gsgcm12;

and solve the eq and value of x