What is the exact value of sinâ¡(157.5°)? negative startfraction startstartroot 2 startroot 2 endroot endendroot over 2 endfraction startfraction startstartroot 2 minus startroot 2 endroot endendroot over 2 endfraction negative startfraction startstartroot 2 minus startroot 2 endroot endendroot over 2 endfraction startfraction startstartroot 2 startroot 2 endroot endendroot over 2 endfraction