Can I have some help with this

4. [a] {4 points} Let L he the line in IR" spanned by the vector {1,1,1,1]I. Find a basis for the orthogonal complement of L. [h] {3 points} Let P be the matrix of the transformation that is projection onto the orthog- onal complement of L in IR\". Describe the image and the kernel of P geometrically and relate their dimensions using rank-nullity. {c} {3 points} Use the method of least squares to nd an approximate solution to the {in- consistent system} Pi = {1, 1, [LE]. (Hint: you don't need to do any complicated matrix multiplication if you go about this the right way)