Weknowfromtrigonometrythat−1≤sin(1x)<−1forallx≠0forlimx→0wedon′tcarewhathappenswhenx=0sincex<2>0forallx≠0,wecanmultiplythroughbyx2toget−x2=x2sin(1x)≤x2Clealylimx→0(−x2)=0andlimx→0x2=0,so,bythesqueezetheorem.limx→0x2sin(1x)=0Hence,therequiredansweris0.