Question

Linear algebra question

Answer 1

Use matrix multiplication to find the image of the vector ( - 8 , 7 , 3) if it is rotated θ = 30 ∘ about the x -axis (counterclockwise).

Let T denote the linear operator rotating each vector through an angle of θ = 30∘ about the x -axis. Then

T( - 8 , 7 , 3) =

Answer 2

I got -8 as the first part but I don't know how to do the rest.