CREATE TABLE table_37982 ("Week" FLOAT, "Date" TEXT, "Time" TEXT, "Opponent" TEXT, "Result" TEXT, "Game site" TEXT, "NFL Recap" TEXT, "Record" TEXT)

What was the Opponent at Arrowhead Stadium?
SELECT "Opponent" FROM table_37982 WHERE "Game site" = 'arrowhead stadium'
SELECT "Opponent" FROM "table_37982" WHERE "Game site" = 'arrowhead stadium'