代码如下:
clc,clear all
x1 = -20:0.01:20;
y1 = x1.^3 + 2*x1.^2 - 3*x1+4;
t = 0:0.01:2*pi;
r = cos(2.*t);
t = 0:0.01:2*pi;
x3 = (1+sin(t)-2.*cos(4*t)).*cos(t);
y3 = (1+sin(t)-2.*cos(4*t)).*sin(t);
x4 = -20:0.01:20;
y4 = sin(x4) + sin(2*x4);
figure('position',[600,150,700,700])
subplot(221)
plot(x1,y1,'r');
title('f(x)=x^{3}+2x^{2}-3x+4')
xlabel('x')
ylabel('f(x)')
grid on
subplot(222)
polar(t,r,'r');
title('r=cos2\Theta')
subplot(223)
plot(x3,y3);
title({'参数方程:';'x=(1+sint-2cos4t)cost';'y=(1+sint-2cos4t)sint'});
xlabel('x')
ylabel('y')
grid on
subplot(224)
plot(x4,y4);
title('y=sinx+sin2x')
xlabel('x')
ylabel('y')
grid on
图像如下:
代码如下:
function f = a_sqrt(a)
x = a;
f = (x+a./x)./2;
while abs(f-x) > 0.00001
x=f;
f = (x+a./x)./2;
end