let be as i found in here. the set is an orthogonal basis for so if you put then would be an orthonormal basis for

let and be the standard basis for the linear transformation you're looking for in basis simply sends to 0 and remain fixed, i.e.Now the next question seems even much harder. I must find a linear transformation such that and .

My attempt : and I'm at a loss.

thus now use what you've learned about "change of basis" to find then the answer to

your question would be: where