At x→4, x3−64x2−16 becomes 00 form Now, limx→4x3−64x2−16 =limx→4x3−43x2−42 =limx→4[x3−43x−4×x−4x2−42] =limx→4[x3−43x−4]limx→4[x2−42x−4] =3(4)3−12(4)2−1[∵limx→axn−anx−a=nan−1] =3(4)22(4)=6
limx→4x3−64x2−16