1、t=-6:6;x=3*a*t./(1+t.2);y=3*a*t.2./(1+t.2);7. 蔓叶线x=3*a*t.2./(1+t.2);y=3*a*t.3./(1+t.2);8. 摆线clc;a=1;b=1;t=0:pi/50:6*pi;x=a*(t-sin(t);y=b*(1-cos(t);9. 内摆线(星形线)2*pi;x=a*cos(t).3;y=a*sin(t).3;plot(x,y) 10. 圆的渐伸线(渐开线)x=a*(cos(t)+t.*sin(t);y=a*(sin(t)+t.*cos(t);11. 空间螺线clearb=2;c=1;x=a*cos(t);y=b*sin(t);
2、z=c*t;plot3(x,y,z)以极坐标方程表示的曲线:12. 阿基米德线phy=0:rho=a*phy;polar(phy,rho,r-*) 13. 对数螺线a=0.1;rho=exp(a*phy);polar(phy,rho) 14. 双纽线phy=-pi/4:pi/4;rho=a*sqrt(cos(2*phy);polar(phy,rho)hold onpolar(phy,-rho) 15. 双纽线pi/2;rho=a*sqrt(sin(2*phy);polar(phy,-rho)16. 四叶玫瑰线closerho=a*sin(2*phy);17. 三叶玫瑰线rho=a*sin(3*
3、phy);polar(phy,rho) 18. 三叶玫瑰线rho=a*cos(3*phy);polar(phy,rho) 实验二极限与导数1 求下列各极限(1) (2) (3)syms ny1=limit(1-1/n)n,n,inf)y2=limit(n3+3n)(1/n),n,inf)y3=limit(sqrt(n+2)-2*sqrt(n+1)+sqrt(n),n,inf) y1 =1/exp(1)y2 =3y3 =0 (4) (5)(6)syms x ;y4=limit(2/(x2-1)-1/(x-1),x,1)y5=limit(x*cot(2*x),x,0)y6=limit(sqrt(x
4、2+3*x)-x,x,inf) y4 =-1/2y5 =1/2y6 =3/2 (7) (8) (9)syms x my7=limit(cos(m/x),x,inf)y8=limit(1/x-1/(exp(x)-1),x,1)y9=limit(1+x)(1/3)-1)/x,x,0) y7 =1y8 =(exp(1) - 2)/(exp(1) - 1)y9 =1/3 2 考虑函数作出图形,并说出大致单调区间;使用diff求,并求确切的单调区间。close;syms x;f=3*x2*sin(x3);ezplot(f,-2,2)大致的单调增区间:-2,-1.7,-1.3,1.2,1.7,2;大致的单
5、点减区间:-1.7,-1.3,1.2,1.7 f1=diff(f,x,1)ezplot(f1,-2,2)line(-5,5,0,0)axis(-2.1,2.1,-60,120)f1 =6*x*sin(x3) + 9*x4*cos(x3)用fzero函数找的零点,即原函数的驻点x1=fzero(6*x*sin(x3) + 9*x4*cos(x3),-2,-1.7)x2=fzero(,-1.7,-1.5)x3=fzero(,-1.5,-1.1)x4=fzero(,0)x5=fzero(,1,1.5)x6=fzero(,1.5,1.7)x7=fzero(,1.7,2)x1 = -1.9948x2 =
6、 -1.6926x3 = -1.2401x4 = 0x5 = 1.2401x6 = 1.6926x7 = 1.9948 确切的单调增区间:-1.9948,-1.6926,-1.2401,1.2401,1.6926,1.9948确切的单调减区间:-2,-1.9948,-1.6926,-1.2401,1.2401,1.6926,1.9948,23 对于下列函数完成下列工作,并写出总结报告,评论极值与导数的关系,(i) 作出图形,观测所有的局部极大、局部极小和全局最大、全局最小值点的粗略位置;(iI) 求所有零点(即的驻点);(iii) 求出驻点处的二阶导数值;(iv) 用fmin求各极值点的确切位
7、置;(v) 局部极值点与有何关系?(1) (2) (3) f=x2*sin(x2-x-2)f =x2*sin(x2 - x - 2) 局部极大值点为:-1.6,局部极小值点为为:-0.75,-1.6全局最大值点为为:-1.6,全局最小值点为:-3axis(-2.1,2.1,-6,20)2*x*sin(x2 - x - 2) + x2*cos(x2 - x - 2)*(2*x - 1)2*x*sin(x2-x-2)+x2*cos(x2-x-2)*(2*x-1),-2,-1.2),-1.2,-0.5),-0.5,1.2),1.2,2) -1.5326 -0.7315 -3.2754e-027 1.
8、5951 ff=(x) x.2.*sin(x.2-x-2)ff(-2),ff(x1),ff(x2),ff(x3),ff(x4),ff(2) ff = (x)x.2.*sin(x.2-x-2)ans = -3.0272 2.2364 -0.3582 -9.7549e-054 -2.2080 0 实验三级数1. 用taylor命令观测函数的Maclaurin展开式的前几项, 然后在同一坐标系里作出函数和它的Taylor展开式的前几项构成的多项式函数的图形,观测这些多项式函数的图形向的图形的逼近的情况syms xy=asin(x);y1=taylor(y,0,1)y2=taylor(y,0,5)y3
9、=taylor(y,0,10)y4=taylor(y,0,15)x=-1:1;y=subs(y,x);y1=subs(y1,x);y2=subs(y2,x);y3=subs(y3,x);y4=subs(y4,x);plot(x,y,x,y1,:,x,y2,-.,x,y3,-,x,y4,linewidth,3)y1 =y2 =x3/6 + xy3 =(35*x9)/1152 + (5*x7)/112 + (3*x5)/40 + x3/6 + xy4 =(231*x13)/13312 + (63*x11)/2816 + (35*x9)/1152 + (5*x7)/112 + (3*x5)/40 +
10、 x3/6 + x (2) y=atan(x);y1=taylor(y,0,3)y2=taylor(y,0,5),y3=taylor(y,0,10),y4=taylor(y,0,15),3) xx - x3/3x9/9 - x7/7 + x5/5 - x3/3 + xx13/13 - x11/11 + x9/9 - x7/7 + x5/5 - x3/3 + xy=exp(x2);x2 + 1x4/2 + x2 + 1x8/24 + x6/6 + x4/2 + x2 + 1x14/5040 + x12/720 + x10/120 + x8/24 + x6/6 + x4/2 + x2 + 1 y=
11、sin(x)2;x=-pi:pi;x2 - x4/3- x8/315 + (2*x6)/45 - x4/3 + x2(4*x14)/42567525 - (2*x12)/467775 + (2*x10)/14175 - x8/315 + (2*x6)/45 - x4/3 + x2y=exp(x)/(1-x);0;(5*x2)/2 + 2*x + 1(65*x4)/24 + (8*x3)/3 + (5*x2)/2 + 2*x + 1(98641*x9)/36288 + (109601*x8)/40320 + (685*x7)/252 + (1957*x6)/720 + (163*x5)/60 +
12、 (65*x4)/24 + (8*x3)/3 + (5*x2)/2 + 2*x + 1(47395032961*x14)/17435658240 + (8463398743*x13)/3113510400 + (260412269*x12)/95800320 + (13563139*x11)/4989600 + (9864101*x10)/3628800 + (98641*x9)/36288 + (109601*x8)/40320 + (685*x7)/252 + (1957*x6)/720 + (163*x5)/60 + (65*x4)/24 + (8*x3)/3 + (5*x2)/2 +
13、2*x + 1 (6) y=log(x+sqrt(1+x2);x - x3/6(35*x9)/1152 - (5*x7)/112 + (3*x5)/40 - x3/6 + x(231*x13)/13312 - (63*x11)/2816 + (35*x9)/1152 - (5*x7)/112 + (3*x5)/40 - x3/6 + x 2. 求公式中的数的值.k=4 5 6 7 8;symsum(1./n.(2*k),1,inf) pi8/9450, pi10/93555, (691*pi12)/638512875, (2*pi14)/18243225, (3617*pi16)/325641
14、566250 3. 利用公式来计算的近似值。精确到小数点后100位,这时应计算到这个无穷级数的前多少项?请说明你的理由.解:Matlab代码为epsl=1.0e-100;ep=1;fn=1;n=1;while epepsla=a+fn;n=n+1;fn=fn/n;ep=fn;endfnvpa(a,100)n fn = 8.3482e-1012.71828182845904553488480814849026501178741455078125n = 70 精确到小数点后100位,这时应计算到这个无穷级数的前71项,理由是误差小于10的负100次方,需要最后一项小于10的负100次方,由上述循环
15、知n=70时最后一项小于10的负100次方,故应计算到这个无穷级数的前71项.4. 用练习3中所用观测法判断下列级数的敛散性epsl=0.000001;N=50000;p=1000;Un=1/(n2+n3);s1=symsum(Un,1,N);s2=symsum(Un,1,N+p);sa=vpa(s2-s1);sa=setstr(sa);sa=str2num(sa);fprintf(级数)disp(Un)if sa disp(收敛else发散end 级数1/(n3 + n2)收敛 s=;for k=1:100s(k)=symsum(1/(n3 + n2),1,k);plot(s,.) Un=1
16、/(n*2n);end 级数1/(2n*n)收敛 s(k)=symsum(1/(2n*n),1,k);) (3) epsl=0.00000000000001;p=100;Un=1/sin(n);if abs(sa)级数1/sin(n)发散 s(k)=symsum(1/sin(n),1,k);发散 (4) epsl=0.0000001;Un=log(n)/(n3);级数log(n)/n3收敛 s(k)=symsum(log(n)/n3,1,k);(5) he=0;he=he+factorial(k)/kk;s(k)=he;) (6)Un=1/log(n)n;s1=symsum(Un,3,N);s2=symsum(Un,3,N+p);级数1/log(n)n收敛 for k=3:s(k)=symsum(1/log(n)n,3,k);(7) Un=1/(log(n)*n);
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