Comparing values of 2 matrices and finding where they are equal corresponding to values of another matrix, beta

I want to compare the values of cp_found, a matrix, with the values of CpM, another matrix, and find for which value(s) of beta, a matrix, the two are the same. This is what I have so far, but am unable to find the value of beta that makes the 2 matrices equal. Any help is appreciated.

%%Values of lambda (for lamba different of optmiun or Cp no optimun or Wind Speed:11,7 m/s up to 15 m/s and down to 11,7 m/s

%Define Values of Lambda(That we found , this value are in the table excel)

lambda_found = [7.943485689; 7.876168014; 7.809981728; 7.744898547; 7.680891121; 
    ...
    7.876168014; 7.943485689];

cp_found = [0.3862077656; 0.3764718995; 0.3670605433; 0.3579602882; 0.3491583852;
    ...
    0.3764718995; 0.3862077656];
%%Calculus for find 
while k<17

   beta2(k,1)=j;
  Cp0=(-4.1909e-1) + (2.1808e-1).*lambda + (-1.2406e-2).*lambda.^(2) + (-1.3365e-4).*lambda.^(3)+(1.1524e-5).*lambda.^(4);
  Cp1=(-6.7606e-2).*beta2(j,1) + (6.0405e-2).*beta2(j,1).*lambda + (-1.3934e-2).*beta2(j,1).*lambda.^(2) + (1.0683e-3).*beta2(j,1).*lambda.^(3) + (-2.3895e-5).*beta2(j,1).*lambda.^(4)
  Cp2=(1.5727e-2).*beta2(j,1).^(2) + (-1.0996e-2).*beta2(j,1).^(2).*lambda + (2.1495e-3).*beta2(j,1).^(2).*lambda.^(2) + (-1.4855e-4).*beta2(j,1).^(2).*lambda.^(3) + (2.7937e-6).*beta2(j,1).^(2).*lambda.^(4);
  Cp3=(-8.6018e-4)*beta2(j,1).^(3) + (5.7051e-4).*beta2(j,1).^(3).*lambda + (-1.0479e-4).*beta2(j,1).^(3).*lambda.^(2) +(5.9925e-6).*beta2(j,1).^(3).*lambda.^(3) +  (-8.9194e-8).*beta2(j,1).^(3).*lambda.^(4);
  Cp4= (1.4787e-5)*beta2(j,1).^(4) + (-9.4839e-6).*beta2(j,1).^(4).*lambda + (1.6167e-6).*beta2(j,1).^(4).*lambda.^(2) +(-7.1535e-8).*beta2(j,1).^(4).*lambda.^(3) + (4.9686e-10).*beta2(j,1).^(4).*lambda.^(4);
  CpM = Cp0 + Cp1 + Cp2 + Cp3 + Cp4;

end