:A(a,b),a=rcost,b=rsint
A按逆时针方向旋转α,得到B(X,Y)
有:X=rcos(t+α)=r*costcosα-r*sintsinα=acosα-bsinα
Y=rsin(t+α)=r*costsinα+r*sintcosα=asinα+bcosα 满意给分啊!
:A(a,b),a=rcost,b=rsint
A按逆时针方向旋转α,得到B(X,Y)
有:X=rcos(t+α)=r*costcosα-r*sintsinα=acosα-bsinα
Y=rsin(t+α)=r*costsinα+r*sintcosα=asinα+bcosα 满意给分啊!