If y=x2+x+1x2−x−1, then (x2−x−1)2y1=
If y=[x2+2x3x−4], then dydx=?
If y=[x2+1x+1], then dydx=?
(1x+1y)(1x−1y)=? (a) (1x2−1y2) (b) (1x2+1y2) (c) (1x2+1y2−1xy) (d) (1x2−1y2+1xy)