Create a vector A by assigning a list of elements in square brackets. Use the colon(:) followed by the equal(=) sign := 

Create a second vector, B 

Add the two vectors 

Subtract them 

Now load the linear algebra library  

Now take the dot or inner product using the innerprod(...) function 

Compute the Euclidean Norm of A using the norm(...,2) function. 2 signifies the Euclidean norm.  

Now try the cross product using the crossprod(...) function 

The cross product is perpendicular to either vector so 

The angle between A and B can be computed using the angle(...) function 

Or we can use the book definition  

Are they the same? 

Use evalf to evaluate each one. 

Hmmm...pretty close. Just realize that the values within the arccos(...) are the same so the answers really are the same.  

Different algorithms produce different rounding results 

Clear A and B. Assigning a variable to itself in quotes, clears the variable 

Now make two generic vectors. (To create the subscript use shift hyphen to drop the into subscript mode) 

Now perform the dot product, norm and cross product to get the book formulas.