例若f'(x)=A,f(x)=B,求 (1)lim f(xo+3h)-f(xo) h-→0 h (2)lim f(x+2h)-f(x。-h) -→0 h (3)1im f2(x。+2h)-f2(x0-h) h-→0 h 例若mf+创f-m=0, 能否推出 h30 h f'(x)=0?例 若 ′ 0 = 0 = BxfAxf ,)(,)( 求 h xfhxf h )()3( lim)1( 0 0 0 + − → h hxfhxf h )()2( lim)2( 0 0 0 + − − → h hxfhxf h )()2( lim)3( 0 2 0 2 0 −−+ → 例 若 0 0 0 ( )( ) lim 0, h fx h fx h → h + − − = 0 f x ′( ) 0? 能否推出 =