Question

Use a Mathlab program using the while/for command and run it for the following exercise. 20. A twin primes is a pair of prime numbers such that the difference between them is2 (for example, 17 and 19). Write a computer program that finds all the twin primes between 10 and 500. The program displays the results in a two- column matrix in which each row is a twin prime. Do not use MATLAB's built-in function is prime.

Answer 1

twins=[];
j=1;
for i=10:498
    if checkPrime(i) && checkPrime(i+2)
        twins(j,:)=[i,i+2];
        j=j+1;
    end
end
disp(twins)
function [check]=checkPrime(num)
check=0;
for i = 2:sqrt(num)
    if rem(num,i)==0
        check=1;
        break
    end
end
if check==1
    check=false;
else
    check=true;
end
end

twinPrime.m+ Users Vaibhav Documents MATLAB2 twins= [ ] ; Command Window >> twinPrime 13 19 31 43 61 73 101 103 107 109 137 139 149 151 179 181 191 193 197 199 227 229 239 241 269 271 281 283 311 313 347 349 419 421 431 433 461 463 for i=10:498 if checkPrime (i) && checkPrime (i+2) 17 29 41 59 71 twins (j' :)-i,i+2]; 5-j+1 end end 9disp (wins) 10 function [check] checkPrime (num) check 0: for ǐ 2:sqrt (num) 12- 13 14 15- if rem (num, 1)-=0 check=1 ; break end end if check-l check-false; 20 21- 22 end 23 else check-true end >y