matlab第四章部分课后答案.pdfVIP

第四章 1. A=input('输入四位整数A'); Sign=1; if A<0 Sign=-Sign; A=Sign*A; end b=fix(A/1000); B=rem(b+7,10); c=fix(rem(A,1000)/100); C=rem(c+7,10); d=fix(rem(A,100)/10); D=rem(d+7,10); e=rem(A,10); E=rem(e+7,10); A=D*1000+E*100+B*10+C A=Sign*A; 2. a=input('a='); b=input('b='); c=input('c='); x=input('0.5=<x<5.5='); if x>=0.5 &x<1.5 y=a*x^2+b*x+c elseif x>=1.5 &x<3.5 y=a*sin(b)^c+x elseif x>=3.5 &x<5.5 y=log(abs(b+c/x)) else disp('input error'); end a=input('a='); b=input('b='); c=input('c='); x=input('0.5=<x<5.5='); switch round(x) case{1} y=a*x^2+b*x+c case {2,3} y=a*sin(b)^c+x case{4,5} y=log(abs(b+c/x)) otherwise disp('input error'); end 3. A=floor(rand(1,20)*89+10) A = 11 76 49 92 51 47 85 56 28 69 84 11 70 43 84 54 73 48 37 26 B=A(A<mean(A)&rem(A,2)= =0) B = 28 54 48 26 4. NUM=7; a=zeros(1,NUM); for i=1:NUM a(i)=input('请输入'); end Max=a(1); Min=a(1); for i=2:NUM; if a(i)>Max Max=a(i); end if a(i)<Min Min=a(i); end end % 如果用max,min 函数求，就直接写下一句 % Max=max(a); % Min=min(a); Max Min 5. 循环结构: s=0; n=63; for i=0:63 s=s+2^i; end s 1.8447e+019 调用sum 函数: n=63; i=0:n; f=2.^i; s=sum(f)