Question

用Matlab怎么画给定函数的图像呢？

Answer 1

syms
x
x0
k=4.6651-0.5074*x.^4+8.1055*x.^3-40.6303*x.^2+90.2343*x
%subplot(m,n,i)生成m×n个子图窗口，i是每个窗口的index
%%%%%%%%%%%%%%%%%%%%%%%%%%
subplot(3,2,1);%1
ezplot(k);
hold
on
x0=ceil(9*rand)
%k0=str2num(subs(k,x,x0))
plot(double(x0),subs(k,x,x0),'ro');hold
off
%%%%%%%%%%%%%%%%%%%%%%%%%%
subplot(3,2,2);%2
ezplot('sin(x)');
%
%%%%%%%%%%%%%%%%%%%%%%%%%%
subplot(3,2,3);%3
ezplot('cos(x)');
%%%%%%%%%%%%%%%%%%%%%%%%%%
subplot(3,2,4);%4
ezplot('e^x');
%%%%%%%%%%%%%%%%%%%%%%%%%%
subplot(3,2,[5
6]);%第5和第6个窗口合并
%u=1:0.1:10
plot(1:0.1:10,tan(u),'b')
------------------------
你研究一下

Answer 2

数值积分
以下代码供参考。你应仔细检查，看相关函数有没有写错。
% 被积函数
f = @(x,t) 9/80*(1-x.*x/200^2).^1.5.*(1-150*t/100^2./(1-x.*x/200^2)).^1.5;
b = @(x) sqrt(100*100*(1-x.*x/200/200))/50 ; % 积分上限
q = @(x) quadgk(@(t) f(x,t) ,0, b(x) ); % 数值积分
b = 0:0.5:199; % x取值
qx = arrayfun(@(x) q(x),b); % x对应的积分值
plot(b,qx) %绘图