**TI89**analyseFunction file 02/25/05, 19:38Rdiffˆ2vÒ¥Zxéäè(-åˆxðˆfðÅ ã)¼-ˆxð ã+(-åˆyðˆfðÅ ã)¼-ˆyð ããããããããèexp,var1,var2æèäåˆyˆxˆfÜt,