靠,高数的题,
limit x→0 [ f(ax)-f(-ax)]/x=lim x→0 [ f(ax)-f(0)+f(0)-f(-ax))]/x
=lim x→0{ [ f(ax)-f(0)]/x+f(0)-f(-ax))]/x}
=lim x→0{ [ f(ax)-f(0)]/x+lim x→0{ [ f(0)-f(-ax)]/x
=af'(0)-(-af'(0))=2af'(0)
靠,高数的题,
limit x→0 [ f(ax)-f(-ax)]/x=lim x→0 [ f(ax)-f(0)+f(0)-f(-ax))]/x
=lim x→0{ [ f(ax)-f(0)]/x+f(0)-f(-ax))]/x}
=lim x→0{ [ f(ax)-f(0)]/x+lim x→0{ [ f(0)-f(-ax)]/x
=af'(0)-(-af'(0))=2af'(0)