ߵѧ
ڶ һԪѧ
2.1
ףҪ һָ 1Ķ
躯y?f(x)ڵx0ijж壬Աxx0?xӦغ?y?f(x0??x)?f(x0)
f(x0??x)?f(x0)?y?lim
?x?0?x?x?0?xlimڣƴ˼ֵΪf(x)x0ĵҲ̣f?(x0)y?x?x0
dydxx?x0
df(x)dxx?x0ȣƺy?f(x)ڵx0ɵļڣ
ƺy?f(x)ڵx0ɵ
һȼʽx?x0??x?x?x?x0
f?(x0)?f(x?)fx0() limx?x0x?x0Ҳർ ҵf??(x0)?lim?x?x0f(x)?f(x0)f(x0??x)?f(x0) ?lim??x?0x?x0?xf(x)?f(x0)f(x0??x)?f(x0) ?lim??x?0x?x0?xf??(x0)?lim?x?x0
f(x)ڵx0ɵ?f(x)ڵx0ҵԴȡ
2ļ
y?f(x)ڵx0f?(x0)ڣڼf?(x0)ʾy?f(x)ڵ㣨x0,f(x0)ߵбʡ ߷̣y?f(x0)?f?(x0)(x?x0)
24
ߵѧ
߷̣y?f(x0)??1(x?x0)(f?(x0)?0) ?f(x0)ֱ˶ʱ·SʱtĺϵΪS?f(t)f?(t0)ڣf?(t0)ʾʱt0ʱ˲ʱٶȡ
3Ŀɵ֮Ĺϵ
y?f(x)ڵx0ɵf(x)ڵx0һ֮Ȼ
y?f(x)ڵx0ȴһڵx0ɵ磬y?f(x)?|x|x0?0
ȴɵ
4ֵĶ
躯y?f(x)ڵx0?xʱ?y?f(x0??x)?f(x0)ıʽ
?y?A(x0)?x?o(?x) ?x?0
o(?x)?x?0ʱ?x߽СA(x0)Ϊ?xΪأf(x)x0
?yеҪԲA(x0)?xΪf(x)x0֣dyǶԱdx?x
5ֵļ
x?x0df(x)x?x0
?y?f(x0??x)?f(x0)y?f(x)ڵx0Ӧ
Ա?xf(x0)dyx?x0
y?f(x)ڵM0(x0,f(x0))ߵӦ
ͼ
6ɵĹϵ
f(x)x0?f(x)x0ɵ
dyx?x0?A(x0)?x?f?(x0)dx
һأy?f(x)dy?f?(x)dx
25
ߵѧ
Եf?(x)?dyҲΪ̵̣֮ĺ塣 dx
7߽ĸ
y?f(x)ĵy??f?(x)ڵx0ǿɵģy??f?(x)ڵx0ĵΪy?f(x)ڵx0Ķy??f(x)ڵx0ɵ
y?f(x)n?1ĵڣΪy?f(x)ny(n)
(n)x?x0d2yf??(x0)
dx2x?x0ȣҲ
ydny(x)nȣʱҲy?f(x)nɵ
dx
ּ 1ֱԣ 2ֵ㷨
1ֹʽ 2ʽ
3Ϻֹʽ 4 5
6òʾʽ
ң
һõ
f(x)?(x?a)g(x)g(x)x?af?(a) ⣺f?(a)?limx?af(x)?f(a)(x?a)g(x)?0?lim?g(a) x?ax?ax?a
ֶκڷֶε㴦Ŀɵ 1 躯
?x2,x?1f(x)??
?ax?b,x?1ȷabֵʹf(x)ڵx?1ɵ
⣺߿ɵһf(x)x?1Ҳġ
f(x)?limx?1 f(1?0)?lim??x?1x?1226
ߵѧ
f(1?0)?limf(x)?lim(ax?b)?a?b ??x?1x?1Ҫʹf(x)ڵx?1a?b?1b?1?a
f(x)?f(1)x2?1?lim?lim(x?1)?2 f??(1)?lim??x?1?x?1x?1x?1x?1f??(1)?lim?x?1f(x)?f(1)ax?b?1a(x?1)?lim?lim?a x?1?x?1?x?1x?1x?1Ҫʹf(x)ڵx?1ɵf??(1)?f??(1)2?a.
ʵa?2,b?1?a?1?2??1ʱf(x)ڵx?1ɵ.
x2en(x?1)?ax?b2 f(x)?limabΪֵʱf(x)ɵf?(x)
n??en(x?1)?1n(x?1)??? ⣺x?1ʱlimen??x?1ʱlimen(x?1)?0
n???x2,x?1??a?b?1,x?1 f(x)??2?x?1??ax?b,f(x)?limx2?1f(1)?x?1ԣlim??x?1x?1a?b?1?1֪a?b?1 2x?1ɵԣ
x2?f(1)f??(1)?lim
x?1?x?1f??(1)?lim?x?1(ax?b)?f(1)
x?1f??(1)?f??(1)
شf??(1)?lim?x?12x?2 1a?a a?2 x?11b?1?a??1 f??(1)?lim? 27