Use Theorem 4.3.2 to find the matrix B of the linear transformation T ( f ) = f^{\prime} + f^{\prime \prime}Β from P_2 to P_2 with respect to the standard basis π = (1, x, x^2); see Example 1.
By Theorem 4.3.2, we have
B=\begin{bmatrix}[T(1)]_π &[T(x)]_π &[T(x^2)]_π \end{bmatrix}.
Now
As in Section 3.4, it is suggestive to write the basis elements 1, x, and x^2 next to the rows of matrix B, while the values T (1) = 0, T (x) = 1, and T (x^2) = 2 + 2x are written above the columns:
\begin{matrix} \ \ \ \ \ \ \ \ \ \ \ \ \ T(1) \ T(x) \ T(x^2)\\ B=\begin{bmatrix} 0&& 1&&2 \\ 0&&0&&2\\0&&0&&0 \end{bmatrix} \end{matrix} \begin{matrix}\\\\1 \\ x \\ x^2 \end{matrix} .
The last column of B, for example, indicates that T (x^2)= 2 Β· 1 + 2 Β· x = 2 + 2x.