Are you in the same class as "Dave" (http://forums.wolfram.com/student-support/topics/442037)?
You already have the correct Mathematica input; leave off the "=". "Free-form input" is for casually typed inputs. It does not understand most Mathematica function names.
See attached notebook.
"Wolfram" is the company name. "Mathematica" is the product.
Attachment: 444818.nb, URL: ,