y=5x^2-9x-2 . . . ??????????????? "vertex" ??????????????? . . . ???? yu want the lo or hi ??????? . . . quadratik equashun giv the zeroes...x=2 or x=-02 . . . thats wot yu kall the "x-intersepts" . . . tu get lo, dy/dx=10x-9=0, 10x=9, so x=0.9 . . . yu get y=-4.05 . . .