An astroid looks like a

rhombus with sides slightly curved in towards the center.

To plot astroid use the following

parametric equations:

x = a *

cos(Q)

^ 3

y = a *

sin(Q) ^ 3

In case you're curious, the

area will be equal to 3

Pi*a^2/8. (You can verify that by

integrating the aforemetioned equation from 0 to Pi/2 and then multiplying by 4 (it's

symmetric)).

To plot in MapleV use the following command:

*plot([4*cos(x)^3,4*sin(x)^3,x=0..2*Pi]);*