# What does the @ symbol do in Mathematica? [duplicate]

I have the folllowing array

$$h = \left(\begin{array}{cccc}1 & 0 & 0 & 0\\ 0 & f^2 & 0 & f^2 \cos\theta\\ 0 & 0 & g^2 & 0 \\ 0 & f^2\cos\theta & 0 & f^2\cos^2\theta + g^2\sin^2\theta\end{array}\right)$$

defined in Mathematica using

h = {{1,0,0,0},{0,f^2,0,f^2 Cos[theta],{0,0,g^2,0},{0,f^ Cos[theta],0,f^2 Cos[theta]^2 + g^2 Sin[theta]^2}};


If I now have a matrix $M$ of the same dimension as $h$, and if I do the following operation:

Mprime = Simplify[M.Inverse@g];


what will this achieve?

More precisely what does the code

Matrix1.Inverse@Matrix2


actually end up doing?

## marked as duplicate by Kuba♦Jun 23 '17 at 8:08

• p.s. lookup Cos and documentation in general because f^2\cos\theta is not close to a valid syntax. – Kuba Jun 23 '17 at 8:11