(1,-1)y=x^2+ax+b-1=1+a+ba+b=-2 (1)y=x^2+ax+by' = 2x+ay'|(1,-1) = 2+a2y=xy^3-12y' = 3xy^2.y' + y^3 y' = y^3/(2-3xy^2)y'|(1,-1) = -1/(2-3) = 12+a = 1a=-1from (1)a+b=-2-1+b=-2b=-1(a,b)=(-1,-1)