sand dollar. n. 1. Any of various thin circular echinoderms of the order Clypeasteroida, especially Echinarachnius parma, of coastal northern Atlantic and Pacific waters, having a covering of short movable spines.
One reason why linear algebra is very useful is that linear transforms of normal variables are normal. If x ~ N(a, A), then Bx+b ~ N(Ba+b, BABT). In a way, when everything is linear and normal, everything is nice and analytically tractable.
A lot of intermediate algebra is centered on finding the square root and variables of certain equations. Learning how to factor correctly and graph equations are two of the most important skills a student takes away from intermediate algebra. This helps create a solid foundation that makes the content of future algebra courses more easily understood. Intermediate algebra is also used in the ACT Mathematics section.