Expression 6: Start product from "i" equals 0 to "N" , end product, left parenthesis, left parenthesis, StartFraction, "x" times cos left parenthesis, "i" "a" , right parenthesis minus "y" times sin left parenthesis, "i" "a" , right parenthesis Over 4 , EndFraction , right parenthesis squared plus left parenthesis, StartFraction, "x" times sin left parenthesis, "i" "a" , right parenthesis plus "y" times cos left parenthesis, "i" "a" , right parenthesis Over 1 , EndFraction , right parenthesis squared minus 1 , right parenthesis equals 0N∏i=0x·cosia−y·sinia42+x·sinia+y·cosia12−1=0