I am trying to calculate the product of a vector and an inversed matrix in wolfram alpha:
$\begin{bmatrix}1 & 2 & 3\end{bmatrix}$ * $\begin{bmatrix} -0.5 & 0 & 0 \\ 3 & 1 & 0 \\ 1 & 0 & 1\end{bmatrix}^{-1}$
However, when I enter the following into wolfram-alpha:
{1,2,3}*Inverse[{{-0.5, 0, 0}, {3, 1, 0}, {1, 0, 1}}]
the result is a 3*3 matrix.
Only calculating the inverse first and then entering
{1,2,3}*{{-2,0,0},{6,1,0},{2,0,1}}
produces the correct result $\begin{bmatrix}16 & 2 & 3\end{bmatrix}$
What am I doing wrong?
Best Answer
For mathematica or wolfram alpha, use a "." rather than a "" as this corresponds to a matrix product ( can be ambiguous and often means a pointwise product). Also, you should put your vector as a column vector on the right. ie) A . {1,2,3}