-4 -3 -2 -1 0 1 2 3 4-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

>> x=-pi:0.01:pi ;

>> y=2*sin(x/2)*cos(3*x) ;

>> y=2.*sin(x./2).*cos(3.*x) ;

>> plot(x,y)

>> grid on

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

>> x=-1:0.01:1;

>> y=x.*sin(1./x) ;

>> plot(x,y)

>> grid on

-10 -8 -6 -4 -2 0 2 4 6 8 10-350

-300

-250

-200

-150

-100

-50

0

50

>> x=-10:0.01:10 ;

>> y= -3.*x.^2 + 2.*x

>> plot( x,y)

>> grid on

-8 -6 -4 -2 0 2 4 6 8-20

0

20

40

60

80

100

120

>> x=-7:0.01:7 ;

>> y = 2*x.^2 + 3*x - 5;

>> plot(x,y)

>> grid on

-2 0 2 4 6 8 100

0.5

1

1.5

2

2.5x 10

4

>> x=-1:0.01:10;

>> y=exp(x);

>> plot(x,y)

>> grid on

-6 -4 -2 0 2 4 6-4

-2

0

2

4

6

8

10

yx

>> x=-6:0.01:6 ;

>> y1=1./(x.^2 + 1) ;

>> plot(x,y1)

>> grid on

>> hold on

>> y2=-x+3 ;

>> plot(x,y2)

>> ylabel('y')

>> xlabel('x')

-6 -4 -2 0 2 4 6-200

-150

-100

-50

0

50

100

150

200

250

>> x=-6:0.01:6 ;

>> y1=(x-1/2).*(x).*(x+1) ;

>> plot(x,y1)

>> grid on

>> y2=-x ;

>> hold on

>> plot(x,y2)

-6 -4 -2 0 2 4 6-10

-8

-6

-4

-2

0

2

4

6

8

>> x=-6:0.01:6 ;

>> y1=log(x)+ x;

>> y2=log(x.^2) ;

>> plot(x,y1)

>> hold on

>> grid on

>> plot(x,y2,'r')

-10 -8 -6 -4 -2 0 2 4 6 8 10-20

-15

-10

-5

0

5

>> x=-10:0.01:10;

>> y=sin(x).*cos(x./2);

>> plot(x,y)

>> y1=x-9 ;

>> hold on

>> grid on

>> plot(x,y1,'r')

-8 -6 -4 -2 0 2 4 6 8-4

-3

-2

-1

0

1

2

3

4

>> x=-8:0.01:8 ;

>> y1=sqrt(1-x.^2) ;

>> y2=abs(x)-4 ;

>> plot(x,y1)

>> hold on

>> grid on

>> plot(x,y2,'r')

0 1 2 3 4 5 6 7 8-6

-4

-2

0

2

4

6

8

>> x=0.01:4 ;

>> y=log(x)-x./2 ;

>> plot(x,y)

>> plot(x,y)

>> hold on

>> grid on

>> z=4:0.01:8 ;

>> w=sin(z./2) + z ;

>> plot(z,w,'g')

-4 -3 -2 -1 0 1 2 3 4 5 6-35

-30

-25

-20

-15

-10

-5

0

5

10

15

>> x=-4:0.01:2 ;

>> y=x.^2-4 ;

>> plot(x,y)

>> z=2:0.01:6 ;

>> w=-(z.^2-4) ;

>> hold on

>> grid on

>> plot(z,w,'g')

-4 -2 0 2 4 6 80

10

20

30

40

50

60

>> x=-4:0.01:4 ;

>> y=exp(x);

>> plot(x,y)

>> z=4:0.01:8 ;

>> w=1./(z-1) ;

>> hold on

>> grid on

>> plot(z,w,'g')

-4 -2 0 2 4 6 8-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

>> x=-4:0.01:0;

>> y=(x.^2-2).*(x-2) ;

>> plot(x,y)

>> hold on

>> grid on

>> z=0:0.01:8 ;

>> w=sqrt(z);

>> plot(z,w,'g')

-6 -5 -4 -3 -2 -1 0 1 2-1

0

1

2

3

4

5

6

7

8

>> x=-6:.01:-2 ;

>> y=exp(x) - 1./(x+7) ;

>> plot(x,y)

>> z=-2:0.01:2 ;

>> w=-x+log(abs(x)) ;

>> hold on

>> grid on

>> plot(z,w,'g')

x

y

(x2+y2-1)3 - x2 y3=0

-1.5 -1 -0.5 0 0.5 1 1.5-1

-0.5

0

0.5

1

1.5