Recent content by WednesdayBass

No, it's not from a book, it's from a worksheet I've been given. (a+b)v1 + ... is the coordinates for Ψ(u) in the standard basis of Mat2x2(R). So the coordinate vectors are [u]B = [a;b;c;d] and [Ψ(u)]B = [a+b;a-c;a+c;b-c] which is where I got the 4x4 matrix.

Yeah, I've used that basis to get the coordinates of the matrix u ([a,b;c,d]) and find the matrix which you multiply that coordinate vector by to get the new matrix. I have no idea if that's heading in the right direction or not...

Homework Statement Let Ψ: Mat2x2(R) -> Mat2x2(R) be defined as: [a,b;c,d] -> [a+b, a-c; a+c, b-c] Find a basis for the image of Ψ. Homework Equations None, AFAIK. The Attempt at a Solution I started by using the standard basis, B, for Mat2x2(R) to get [u]B [with u in Mat2x2(R)] as...