第四章第1节1.1.12克第2节1. (1) -f'(xo); (2) f'(xo): (3) 2f'(xo)3.提示:证明f(1)=0,f'(1)=26.(1)不可导点:x=k元(keZ),f"(k元)=-1,f*(k元)=l;(2)不可导点:x=2k元(keZ),"(2k元)=-/2,f(2k元)=/2:(3)不可导点:x=0,f"(0)=1,f(0)=-1;(4)不可导点:x=0,f"(0)=-1,f*(0)=17.(1)可导:(2)a=b=0时可导,其他情况不可导:(3)不可导:(4)a<0时可导,a≥0时不可导11,lim f(x)=00,f(x)=-(-1+ sin-10.(1)不一定;反例:f(x)=+cos-xX->xxxlimf(x)=0不成立.x->0+(2)不一定:反例:f(x)=/第3节3. (1) 3cosx+—-x 2/x(2) cosx-xsinx+2x;(3)(2x+7)sinx+(x2+7x-5)cosx;(4) 2x(3tanx+2sec x)+x2(3sec2 x+2tan xsecx):3.2x2.(5)e"(sinx+cosx)+4sinx-2222(x+2sinx-2*)x3;(6)(1+2cosx-2*In2)x331
第四章 第 1 节 1.1.12克. 第 2 节 1.(1) '( ) ;(2) ;(3) . 0 − f x '( ) 0 f x 2 '( ) 0 f x 3.提示:证明 f (1) = 0 , f '(1) = 2 . 6.(1)不可导点: x = kπ (k ∈ Z) , ′( ) = −1 f− kπ , ′( ) =1 f+ kπ ; (2)不可导点: x = 2kπ (k ∈ Z) , f− ′(2kπ ) = − 2 , f+ ′(2kπ ) = 2 ; (3)不可导点: x = 0, ′(0) =1 −f , ′(0) = −1 +f ; (4)不可导点: x = 0, ′(0) = −1 −f , ′(0) =1 +f . 7.(1)可导;(2)a = b = 0时可导,其他情况不可导;(3)不可导;(4) 时可导, 时不可导. a < 0 a ≥ 0 10.(1)不一定;反例: x x f x 1 cos 1 ( ) = + , = ∞ → + lim ( ) 0 f x x , ) 1 ( 1 sin 1 '( ) 2 x x f x = − + , = ∞不成立. → + lim '( ) 0 f x x (2)不一定;反例: f (x) = x . 第 3 节 3.(1) x x x 2 1 1 3cos + − ; (2)cos x − xsin x + 2x ; (3)(2x + 7)sin x + (x 2 + 7x − 5)cos x ; (4)2x(3tan x + 2sec x) + x 2 (3sec2 x + 2 tan xsec x) ; (5) 2 3 2 3 (sin cos ) 4sin − e x + x + x − x x ; (6) 3 5 3 2 ( 2sin 2 ) 3 2 (1 2cos 2 ln 2) − − + x − x − x + x − x x x ; 1
sinx-1(7)(x+cosx)?2(xsin x + x2 cosx-2)(/x +1)- Vx(xsin x-2lnx)(8)2x(/x +1)2(3x2 -csc2 x)xInx-x3 -cotx,(9)xlnx-2(x+sin xcos x)(10) (xsinx-cosx)?)arcsinx+(e*+ Inx)(11) (e +xln3In33.(12)-xshx(cotxcscx+)+x(cscx-3lnx)(2shx+xchx)(13) (I+ an x sec x)(x cse x) -(x + sec x)(1+ cot xcse x),(x-csc x)2(14) (+x")+cosx)arctanx-(+sinx)(1+ x)arctan? x5.提示:设切点为(xo,xo),f(x)=log。x,利用f(xo)=x与f(xo)=1解出xo与aJim (x)=!6.7. S, = (x,y)la(ax2 +bx+c- y)>0),S, = (x, )[ax2 +bx+c- y=0),S; = (x,y)[a(ax? +bx+c-y)<0)第4节1. (1) 2(2x2 -x+1)(4x-1) :(2) e2*(3cos3x+2sin3x):(3) -号x(1+x)2
(7) 2 ( cos ) sin 1 x x x + − ; (8) 2 2 2 ( 1) 2( sin cos 2)( 1) ( sin 2ln ) + + − + − − x x x x x x x x x x x ; (9) x x x x x x x x 2 2 2 3 ln (3 − csc ) ln − − cot ; (10) 2 ( sin cos ) 2( sin cos ) x x x x x x − − + ; (11) 2 1 1 ) ln3 ln )arcsin ( ln3 1 ( x x x e x ex x − + + + ; (12) ) (csc 3ln )(2sh ch ) 3 sh (cot csc 2 x x x x x x x − x x x x + + − + ; (13) 2 ( csc ) (1 tan sec )( csc ) ( sec )(1 cot csc ) x x x x x x x x x x − + − − + + ; (14) x x x x x x x 2 2 2 (1 )arctan (1 )(1 cos )arctan ( sin ) + + + − + . 5.提示:设切点为(x0 , x0 ) , f x x a ( ) = log ,利用 0 0 f (x ) = x 与 '( ) 1解出 与a . f x0 = 0 x 6. e y xn n 1 lim ( ) = →∞ . 7. {( , ) | ( ) 0} 2 S1 = x y a ax + bx + c − y > , {( , )| 0} 2 S2 = x y ax + bx + c − y = , {( , )| ( ) 0} 2 S3 = x y a ax + bx + c − y < . 第 4 节 1.(1)2(2x 2 − x +1)(4x −1) ; (2)e 2x (3cos3x + 2sin 3x) ; (3) 2 3 2 3 (1 ) 2 3 − − x + x ; 2
1-lnx(1(4)2xInx(5) 3x2 cosx3;_ sin Vx(6)2Vxx-1-/1+x(7)2/1+x(x+/1+x)-2x(8)Ve2x -12(x* +1)(9)x(x4 1)(10) =2(4x + cos x)(2x2 + sin x)3(11) 2(1-")Inx-(+In’ x)(1-2x*)x2(1-x3)1+cscx?+x2csc x?cotx2(12)(1+ cscx2)258号(2*-1)_-2(3*+1),(13)34(14) -sin2x-e-sinx;2x4-3a2x2 +a4+a2(15)3(a? -x2)2Na? -x?a>01x22. (1) cotx; (2) cscx; (3)(4)Vx?+aa<oVa?-y222折1f'(x)f'(x)3. (1)x3f(x3);(2)): (3)(4)3xln2 xInx2/f(x)1+ f2(x)(5) 2xe*f(e")f'(f(er): (6) cos(f(sinx)f'(sinx)cosx;3
(4) 2 1 2 2 ln 1 ln ⎟ ⎠ ⎞ ⎜ ⎝ − ⎛ x x x x ; (5) ; 2 3 3x cos x (6) x x 2 sin − ; (7) 2 1 ( 1 ) 1 1 x x x x x + + + − − + ; (8) 1 2 2 2 − − x e x ; (9) ( 1) 2( 1) 4 4 − + x x x ; (10) 2 3 (2 sin ) 2(4 cos ) x x x x + − + ; (11) 2 3 2 2 2 2 2 (1 ) 2(1 )ln (1 ln )(1 2 ) x x x x x x − − − + − ; (12) 2 3 2 2 2 2 2 (1 csc ) 1 csc csc cot x x x x x + + + ; (13) 4 5 3 2 3 4 2 (3 1) 4 27 (2 1) 3 8 − − − x x − − x x + ; (14) x e x ;2 sin sin 2 − − ⋅ (15) 2 3 2 2 4 2 2 4 2 ( ) 2 3 a x x a x a a − − + + . 2.(1)cot x ;(2)csc x ;(3) ⎪ ⎩ ⎪ ⎨ ⎧ < − − − > 0 0 2 2 2 2 2 a a x x a x a ;(4) 2 2 1 x + a ;(5) 2 2 x − a . 3.(1) '( ) 3 2 3 2 3 1 x f x − ;(2) ) ln 1 '( ln 1 2 x f x x − ;(3) 2 ( ) '( ) f x f x ;(4) 1 ( ) '( ) 2 f x f x + ; (5)2 '( ) '( ( )) ;(6) ; 2 2 2 x x x xe f e f f e cos( f (sin x)) f '(sin x)cos x 3
: (8) -[(f()F(x)(7) -(x)f2(x)(r(f(x)f(x)4. (1) (1+Inx)x*;[3x?+cosxIn(x3 + sin x)(2) (x3 +sinx)*x2x(x3 +sinx)(3)(Incosx-xtanx)cosx2xIn In(2x + 1)+ln*(2x+1) :(4)(2x +1)In(2x +1)3x2x1-xx(51- x22(1+x3)V1+(6)I(x-x.)i=ix-x,i=l2+Inx,/xcOsxVi(7)2/x1+ y2y? +yey1+2(sin y-x)5. (1)(2)(3)(41+xeyy2(siny-x)cosy-siny1-x-X)2xersec(x+)-~; (7) _2 cosx+ylny ;(5)(6)x+2ysinxx-sec(x+y)er'+y-2xyay-x?(8)y2-ax3bt3f2 _1-tsint+2costb218. (1)(2)(5)-tant;2a2ttcost+2sinta1+tbshbt(sint-cost)tant1(10)(6)(7)-1; (8)(9)2achatsint+cost13. (1) [f'(u)g(u)h(u)+ f(u)g'(u)h(u)+ f(u)g(u)h'(u)p'(x)dx ;(2) ()g()h()+ (u)g(w)h(u)- (u)g(u)h(a)p'(x)dx ;(h(u)? gg) (d:(3) h(u)8()h(u)4
(7) ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ − ( ) 1 ' ( ) '( ) 2 f x f f x f x ;(8) ( )2 ( ( )) '( ( )) '( ) f f x f f x f x − . 4.(1)(1+ ln x)x x ; (2) ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ + − + + + 2 3 3 2 1 3 ln( sin ) ( sin ) 3 cos ( sin ) x x x x x x x x x x x ; (3)( ) ln cos x − x tan x cos x x ; (4) ln (2 1) (2 1)ln(2 1) 2 lnln(2 1) + ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ + + + + x x x x x x ; (5) ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ + − − − + − 2(1 ) 3 1 1 1 1 3 2 2 3 2 x x x x x x x x ; (6)∏ ∑ = = − − ⋅ n i n i i i x x x x 1 1 1 ( ) ; (7) x x x x x x cos 2 2 + ln . 5.(1) 2 2 1 y + y ;(2) y y xe e + − 1 ;(3) y x y y y x 2(sin )cos sin 1 2(sin ) − − + − ;(4) x xy y y − − + 1 2 ; (5) e xy xe y x y x y 2 2 2 2 2 − − − + + ;(6) sec ( ) sec ( ) 2 2 x x y x y y − + + − ;(7) x y x y x y y 2 sin 2 cos ln 2 + + − ; (8) y ax ay x − − 2 2 . 8.(1) a bt 2 3 ;(2) t t 2 3 1 2 − ;(3) t t t t t t cos 2sin sin 2cos + − + ;(4) t e a b 2 − ;(5)− tan t ; (6) a at b bt ch sh ;(7)−1;(8) t t − + − 1 1 ;(9) t t t t t sin cos (sin cos )tan + − ;(10) 2 t . 13.(1)[ f '(u)g(u)h(u) + f (u)g'(u)h(u) + f (u)g(u)h'(u)]ϕ'(x)dx ; (2) x dx h u f u g u h u f u g u h u f u g u h u '( ) ( ( )) '( ) ( ) ( ) ( ) '( ) ( ) ( ) ( ) '( ) 2 ϕ + − ; (3) g u h u x dx h u h u h u g u g u '( )ln ( ) '( ) ( ) '( ) ( ) ( ) ( ) ⎥ϕ ⎦ ⎤ ⎢ ⎣ ⎡ + ; 4
h(u)g*(u)Inh(u)-h(u)g(u)ng()p(x)dx :(4)h(u)g(u) n° h(u)(5) [(h)-r( g(x)da :f'(u)+h (u)F(u)f'(u)+h(u)h'(u)(6)p'(x)dx(f?(u) + h2(u)2第5节1. (1) y"=6;(2)j"=7x2+12x2 nx;3x2+8x+8(3)54(1 + x)2(4) y"= 6lnx-5x4(5)y"=6xcosx3_9x*sinx3yl=-54x3 sin x3-(27x6-6)cosx31-1x)cos/x-14(6) "= (6x-x2sinx:44x)cos/x+(57,*"= (6_ 15,x2)sin/xYS88(7) y*"=(27x2 +54x+18)e3xx(4x2-Y(8)y"=2(2x2 -1)arcsinx+(1- )(9) j(80) =280|x(x2-4740)cos2x+(120x2-61620)sin2xl(10)y(99)=(2x2+19405)chx+396xshx2. (1) y() =2"-10"sin(20x+"1,元)25
(4) x dx h u g u h u h u g u h u h u g u g u '( ) ( ) ( )ln ( ) ( ) '( )ln ( ) '( ) ( )ln ( ) 2 ϕ − ; (5) x dx f u h u f u h u f u h u '( ) ( ) ( ) '( ) ( ) ( ) '( ) 2 2 ϕ + − ; (6) x dx f u h u f u f u h u h u '( ) ( ( ) ( )) ( ) '( ) ( ) '( ) 2 3 2 2 ϕ + + − . 第 5 节 1.(1) y'''= 6 ; (2) y"= 7x 2 +12x 2 ln x ; (3) 2 5 2 4(1 ) 3 8 8 " x x x y + + + = ; (4) 4 6ln 5 " x x y − = ; (5) y"= 6x cos x3 − 9x 4 sin x3 ; y'''= −54x3 sin x3 − (27x6 − 6)cos x3 ; (6) y x x x x sin x 4 11 )cos 4 1 " (6 2 3 2 = − − ; y x x x x )sin x 8 57 8 1 )cos ( 8 15 ''' (6 2 1 2 3 = − + − ; (7) y'''= (27x 2 + 54x +18)e3x ; (8) 2 2 3 2 2 2 (1 ) (4 3) " 2(2 1)arcsin x e x x x y x x − ⎥ ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎢ ⎣ ⎡ − − = − + ; (9) y 2 [x(x 4740) cos 2x (120x 61620)sin 2x] (80) 80 2 2 = − + − ; (10) y (2x 19405)chx 396xshx . (99) 2 = + + 2.(1) ) 2 1 2 sin(2 ( ) 1 ω ω π − = + − n y x n n n ; 5