Math Is Fun Forum

laipou

Member

Registered: 2009-09-19

Posts: 24

Help me find the cardinality

Let SO(n,R) := {A∈ GL(n;R)|A*At(transpose) = I}
Let T,D, I be the subgroups of SO(3;R) that preserves regular tetrahedron, octahedron, icosahedron respectively.
Determine their cardinality.