function silnia(x) {
    var result1;
    if(x = 0) {
      result1 = 1;
      return result1;
    }

      for (var i = 1; i <= x; i++) {
      result1 *= i;
      }
    return result1;
}

function potega(x, iterNum) {
    var result2 = 1;
      for (var j = 0; j < iterNum; j++) {
          result2 *= x;
      }
    return result2;
}

function mySin(x,iterNum){
  var resultend1 = 0;
  for(var k = 1; k <= iterNum; k += 4){
    resultend1 += ((potega(k,iterNum)/silnia(k)) - (potega(k,iterNum)/silnia(k)));
  }
return resultend1;
}


function myCos(x,iterNum){
  var resultend2 = 0;
    for(var l = 0; l <= iterNum; l += 4){
        resultend2 += ((potega(l,iterNum)/silnia(l)) - (potega(l,iterNum)/silnia(l)));
    }
}


console.log(mySin(3,5));
console.log(myCos(3,5));