Let T: ℝm → ℝn and S: ℝn → ℝp be linear transformations. Then S ∘ T: ℝm → ℝp is a linear transformation. Moreover, their standard matrices are related by [S ∘ T] = [S][T]. Verify the theorem above by finding the matrix of S ∘ T by direct substitution and by matrix multiplication of [S][T]. T x1 x2 = x2 −x1 , S y1 y2 = y1 + 5y2 2y1 + y2 y1 − y2