分别用红、绿、颜色在同一个图形窗口绘制下列函数在区间[-pi, pi]的图形，y=sin(x),y=cos(x),y=tan(x). A. clear x=-pi:0.1:pi; y1=sin(x); y2=cos(x); y3=tan(x); plot(x,y1,'r',x,y2,'g',x,y3,'b') B. clear x=-pi:0.1:pi; y1=sin(x); plot(x,y1,'r') y2=cos(x); plot(x,y2,'g') y3=tan(x); plot(x,y3,'b') C. clear x=-pi:0.1:pi; y1=sin(x); plot(x,y1,'r') hold on y2=cos(x); plot(x,y2,'g') y3=tan(x); plot(x,y3,'b') D. clear x=-pi:0.1:pi; y1=sin(x); plot(x,y1,'r') y2=cos(x); plot(x,y2,'g') y3=tan(x); plot(x,y3,'b') E. clear x=-pi:0.1:pi; y=sin(x); y=cos(x); y=tan(x); plot(x,y,'r',x,y,'g',x,y,'b') F. clear x=-2*pi:0.1:2*pi; y1=sin(x); plot(x,y1,'r') hold on y2=cos(x); plot(x,y2,'g') y3=tan(x); plot(x,y3,'b')