# Can you find a 2-form not written as the wedge of two 1-forms?

I was under the impression that all 2-forms are the wedge $(\wedge)$ of two 1-forms. Is it possible to have a 2-form that you can't write as $A\wedge B$ with $A,B$ 1-forms?

• The question in your title is the opposite of the question in the body of your thread. Mariano is responding to the latter. – Ryan Budney Oct 6 '10 at 2:25

• @JimJones. I assume that $A,B,C,D$ in your first formula are functions... (Maybe I could add to Mariano's answer: simply look at the definition of 2-forms and remember something about linear independence.) – Agustí Roig Oct 6 '10 at 12:52